Electrical / Voltage problem

[1997 Eclipse]

My problem seems to be voltage. When I first turn the car on with A/C the voltage start at approx 13.5v. At night with the lights and stereo on, after 1 - 2 hours of driving, if I come to a stop, my voltage reagding will drop to about 9.9v. If I rev the car the voltage will increase to approx 12 - 13. I have HKS 264/272 and a idle of approx 650 rpm. I have just bought a new alternator from Satan because I thought the initial problem was the alternator. My alternator - batttery cable is original. The stereo (400w amp + 120w amplified Sub) is not conneted to the battery directly, I will change this. What is the problem? Do I have to change the cable. Will grounding wires help.

Dan

 

[Kevin90GSX]

Anytime you are adding more of a voltage to a car that is only equipped for the factory equipment your gonna use more voltage. This is why alot of guys run their amps to their battery directly as well as the rewire for the fuel pump.

Also if you have aftermarket gauges this will also drain some of the battery.

If you have already replaced your alternator I suggest you just do some rewiring of your amp and see what happens with that.

 

[1997 Eclipse]

Kevin,

Thanks for the help. I will rewire my amp and put grounding wires.

Dan

 

[LightningGSX]

Your stock alternator has barely enough output to cover your existing accessories.What ever you do, do not run your wires to the alternator directly.

 

[92redman]

Get a .5 Farad cap?

 

[Kevin90GSX]

Originally posted by 1997 Eclipse
Kevin,

Thanks for the help. I will rewire my amp and put grounding wires.

Dan

no problem. Let me know if that fixes it!

 

[GTM]

Originally posted by 1997 Eclipse
My problem seems to be voltage. When I first turn the car on with A/C the voltage start at approx 13.5v. At night with the lights and stereo on, after 1 - 2 hours of driving, if I come to a stop, my voltage reagding will drop to about 9.9v.
...

My alternator - batttery cable is original. The stereo (400w amp + 120w amplified Sub) is not conneted to the battery directly, I will change this. What is the problem? Do I have to change the cable. Will grounding wires help.
Dan

Ye gads, 520 watts in round numbers is 50 amps, AIN'T no way in h..l can you expect a stock alternator to keep up with that and dirve the car at night.

You need about 35 amps with the lights running, turn the A/C and or heater on you are looking at another 20 amps, with the Alt putting out 70-80 amps max there is no way you can expect to run that system. You have 2 choices, pull the 400 watt out or go to a 100-120 amp alternator which is going to cost you more than the sound system.

I've looked at other alternators and the problem is the belt on the DSM is too narrow for most of the large output units. You migh be able to get away running with a 4 groove(?) belt on a 7 groove(?) pulley if the groove interval is the same. I've never tried this so cannot endorse it as a valid swap. I think the alt shaft is about 1/2" on the stock unit and 5/8" for the larger capacity units thus cannot swap pulley. Grand Caravan and Voyagers ran these extra capacity for the rear A/C and heater blowers but again the pivot bolt may also be larger and require drilling the stock mount. It will be a tight fit though my e&e thinks you might be able to make it work. Also you would need to then find a different length belt with the larger alt frame diameter.

If you do find an alternator that will work and drive everything do let us know for you are not the first person to encounter this problem. You could add a second battery for running the sound system only with a switch / diode pack so it can be charged during the day but doesn't allow the car battery to power the amplifier.

Put some high efficiency speakers in there and forget that arc welding amp.

Cheers,
GTM

 

[turboslug]

I have a 1000w Rockford and a 400w alpine. To combat the electricy problem I have put a Marine battery in the trunk and wired it in series with the front battery. Since then I haven't had any problems with electricity. Just make sure you have good grounds. Wire the amps (just the positive) to the battery and make sure there is one central ground for all the amps and the battery. More than one ground can cause noise in the speakers. I would also make sure to be running a high gauge wire 4awg at the least, you can never be too sure.

 

[1997 Eclipse]

Thanks Guys. I seem to have a minor problem even when the stereo is not turn on. I might go with the idea of a second battery and wire some of the component it it including the stereo.

Dan

 

[GTM]

Originally posted by turboslug
I have a 1000w Rockford and a 400w alpine. To combat the electricy problem I have put a Marine battery in the trunk and wired it in series with the front battery.
...
I would also make sure to be running a high gauge wire 4awg at the least, you can never be too sure.

I just know you didn't wire those batteries in series or you would need a 24 volt system.
Parallel is what you meant, but you should have some sort of a battery isolater in there so you can't drain the car battery down. You can find these at R/V shops for campers, trailers and motorhomes. $10-$20??

And yes use as big a wire as you can afford so you don't have any voltage drop making that 15'-20' run to the back. I just hope you guys don't get any hearing loss from all that power.

And for goodness sakes please turn it down when sitting in traffic... soapbox mode off.

Cheers,
GTM

 

[LightningGSX]

If both batteries are the same brand, type, and age you can just run them parallel without an isolator.And if you decide to put a stiffening capacitor, don't go any less than 1 farad regardless of power output.Maybe try a larger ground from batt to chassis(this helps about %75 of the time)

 

[LightningGSX]

Oh yeah, 520 watts at 13.8 Volts is only about 37 amps

 

[GTM]

Originally posted by LightningGSX
Oh yeah, 520 watts at 13.8 Volts is only about 37 amps

Splitting hairs...


I don't know where the 13.8 comes from, it's not the value assigned to a lead acid battery nor is it charging voltage in the automotive industry.

Under no circumstances would you not add in a safety margin of at least 20% over the maximum load PLUS the value he wants to assign to 1 battery recharge.

Suggesting a 1 farad cap and battery potential being equal is taking too much for granted. I've never seen this done by any professional and I would not like to think of the consequences should that 1 farad cap explode for it will go off like a hand grenade if the Alt decides to run wild and crank out 100v. I can't imagine if there would be much money to be save doing it the right way for he's probably not going to find the cap at Radio Shack.

In endorsing any installation / modification comes the responsibility of knowing the risks and advising the consumer / end user what those are. So he's got this battery sitting in the back unvented tied in with nylon cable ties and a hose clamp. What happens when it starts outgassing... Okay he sticks it in a box and then cuts a couple of 2" holes through the sheet metal and runs the necessary hoses so he doesn't kill anyone.

Nothing has been mentioned of all the additional weight these materials will have with the drivability on some mountain road. Consider 200# behind the rear wheels will make it much more prone to swaping ends even in city driving, put 4 kids in a joy ride could turn into disaster. Now he's got enough power to run all the equipment and instead of him becoming deaf in 10 min it takes him only 5.

I enjoy my music, my kids are very accomplished orchestra musicians. When a piccolo player has a lexan shield placed in front of him so the other musicians do not suffer hearing loss it makes sense to think about the consenquences. That's my 2¢ on the subject, any way he does it will still require at least a 100 amp alt if he is to run that much wattage.

Cheers,
GTM

 

[LightningGSX]

1- 13.8 is the average charging voltage of an automobile
2- 37 amps will almost never actually be drawn.Average current draw will likely be around 15-20 amps, 37 amps I would say exeeds %20 safety margin.20+ amps might exist, but would be in the form of bass transients and a large electrolytic cap could handle those.
3- 1 farad(usually larger) caps are pretty much common place, and has been safely done(by plenty of professionals) for quite some time(10+ years).I can't think of too many situations where you would see 100 volts in an automotive charging system,it's also unlikely 100 volts would instantaneously breakdown the dielectric in a automotive grade electrolytic cap, causing it to grenade.I'm sure there have been accidents with large caps, but I haven't heard of any and I have been in this business for quite some time.
4- Using dual batteries has also been safely done for quite some time, and most batteries used are types that don't require venting.Use optima batteries or similar in trunk mount applications
5- Adding caps and extra batteries can be dangerous, but has been done for so long , there is no shortage of information about using these safely.

 

[GTM]

Originally posted by LightningGSX
1- 13.8 is the average charging voltage of an automobile
2- 37 amps will almost never actually be drawn.Average current draw will likely be around 15-20 amps, 37 amps I would say exeeds %20 safety margin.20+ amps might exist, but would be in the form of bass transients and a large electrolytic cap could handle those.
3- 1 farad(usually larger) caps are pretty much common place, and has been safely done(by plenty of professionals) for quite some time(10+ years).I can't think of too many situations where you would see 100 volts in an automotive charging system,it's also unlikely 100 volts would instantaneously breakdown the dielectric in a automotive grade electrolytic cap, causing it to grenade.I'm sure there have been accidents with large caps, but I haven't heard of any and I have been in this business for quite some time.
4- Using dual batteries has also been safely done for quite some time, and most batteries used are types that don't require venting.Use optima batteries or similar in trunk mount applications
5- Adding caps and extra batteries can be dangerous, but has been done for so long , there is no shortage of information about using these safely.

Ahha, would have helped to have info supporting your position so I did it for you.

http://www.a1bigaudio.com/capacitors.asp

The rational being the need for a faster response that is not available through conventional batteries. The above source shows a diagram and lists the 1 farad cap as a "stiffening" device and being computer grade. Installed with a resistor (no value given) but on the ground side of the Amp.

The verbiage implies that it's something special which is not accurate; however; it most assuredly is in a parallel circuit which in this application must be done.

The resistor value can be achieved using a "lamp" (light bulb) but don't indicate if a tail, stop, or headlight only referencing what the mfg recommends.

I don't agree with the "average" charging voltage as 13.8 for this only leaves .6 volts from a fully charged battery at 13.2. I'm more familiar with 14.3+ from a practical healthy charging system. Yes, I have seen the 13.8 on occasion and considered it on the low side thus causing the Alt. to work a lot harder to charge the battery.

In earlier years of Hitachi alternators regulation was less advanced and I would see the occasional car with every bulb in the car burned out. Only once was I able to witness the actual surge but never able to isolate the exact cause. In that case I replaced what tested as a good alternator and healthy charging system. In the others I only advised should it happen again the Alt. and regulator would need replacing.

As for the 35-37 amps being needed to operate a car after dark isn't hard to understand. A 100 watt headlight is in round numbers 10 Amps x 2 = 20. So you are running 55 watt low and 65 high, on a quad headlight system you are right back with the 20 amps just for headlights. Tail lights are 5 watts and stop lights are 12, parking, side markers, add them all up. Don't forget license plate, dash lights, coils, ECU, injectors etc. and you end up with 35 amps. Turn on the heater blower there is another 15 amps, add the electro-magnetic clutch for the A/C @ 5 amps, and then the cooling fan(s) kicks in so you got another 10-20 amps that's got to come from somewhere. We _ain't_ turned on the radio yet... Because we pulled minimum 175 amps out of the battery to crank the engine over for 5-30 seconds. It's all there and verifiable, sure you don't have your foot on the brakes all the time but all these loads must be calculated and to include charging batterie(s) without overheating the Alt or overworking the diode pack.

Again doing the math how long can the battery last pumping out 100+ amps before it runs out of charge and won't start the car... leaving your headlights on might give a clue for we know they are in the 20-30 amp draw range, good luck after an hour.

The point in all of this was Dan was having electrical problems caused by not understanding where and how they were occurring. He can do _nothing_, which then means he has to pay strict attention when he is using all systems get into the negative numbers. He knows the Alt. won't supply enough output to run the car in a parking lot at high noon with the bass cranked up without some of the draw coming out of the battery and thus running it down. Of course that amplifier isn't always using 1000 watts so he will have to look to the specifications to find the average draw which might only be 350 watts. However if he wants to run the system at night with the A/C on then he has to install the 100-120+ amp Alt. minum and kick his idle speed up to max spec. Since most Alts. don't approach rated capacity until 3,000 rpm and pulley diameters are 2.5-3.0 ratio, idle speed isn't going to sustain the system. Good luck if he can cram a 150 or 180 amp in that confined space. Call up your local highway patrol or ambulance company and ask them how big is their Alt., this will give a clue what they think is reasonable. You will sometimes note they have a fast idle compensator just to overcome the prolonged periods at idle when doing a crash investigation.

Coming back to the battery isolator after reviewing all the givens the more convinced I am it too should be included so he can not worry about having both batteries run down to a no start condition, plus the capacitor is doing nothing towards solving that problem.

Needless to say I've _not_ been involved in installing this type of sound system. I have spent a good many years as a professional mechanic with Master certification, Associate SAE, naval Master carpenter license and rigger, and six pac pilot. There is plenty I don't know and the capacitor trick just illustrates this. In large domestic cars Alt. output may not be an issue however in the smaller "imports" it is an important concern for we Americans tend to disregard energy consumption and how cheap it is to fill up the gas tank to make electricity.

Unfortunately who ever sold Dan the idea didn't care if his car ever started for they were more than willing to take his money for this large system. He also didn't get a professional opinion on whether his Alt. was working fine thus wasted his money in replacing it with what would turn out to be no better than what he had. So he has some serious choices to make as to how much money he can spend to generate the electricity or to only use it sparingly, knowing where and when it won't cause a significant charge loss that he can't make up by turning everything off while his battery builds back up. The use of "you" is for the most part in a plural context, and Dan I am sure is not the only one who has been in this position.

Cheers,
GTM

 

[LightningGSX]

1-I don't know what the link you provided really has to do with anything.They are in fact used in parallel, and a resistor is used only on the initial hookup of the cap(to prevent arcing when power is initially applied).They do in fact make up for SOME lack of alternator output(I would be happy to explain this if required).

2-The current draw of lighting systems? I never disputed this, but as long as we are talking about it...At 14.4 Volts , 2 x 55 watt headlight bulbs=15.2 amps and a 5 watt bulb = 1/3 amp ,where do you get 35 amps?You would need SIXTY 5 watt bulbs and Two 55 watt low beams.65 watt high beams would draw 18 amps, but shoudn't be counted(most headlamp assemblies can't take 100+ watts of heat, so high's and low's are not on at the same time).My amperage in the above post was calculated at 13.8 volts,certainly not a standard but if you took a multimeter to lots of different vehicles this is about the average you would come up with.Also if you were to calculate the amperage at a higher voltage, the amps drawn would be even less- 520 watts at 13.8 volt=37.7 amps and 520 watts at 14.4 =36.1 amps.So given the inefficiency of class AB amplifiers ,assuming a properly adjusted input sensitivity, and %50 average volume level current draw would be about %60-%70 of 36.1 amps.A far cry from your 50.Your current draws are seriously exagerated.

3-A word about higher output alternators..Most higher output alternators actually put out less at idle than your factory alternator.I would about %90 guarantee a large cap(at least 1 farad) and a larger battery to chassis ground cable would take care of his problem.If you switched to a dual battery setup you could add amplifiers too(within reason).And it couldn't hurt to clean your battery connections.

4-Vehicle manufacturers have been using dual battery setups for years(in parallel WITHOUT an isolator).If you don't believe this look at GM trucks(pickups since about 95 w/snow plow prep package and a lot of suv's since the same year).I suppose the OEM's are wrong?

5-I respect your credentials as a mechanic, but I question them in electronics.

6-Sure one person, article, etc. has conflicting views, that must mean the 1000+ shops installing them safely on a daily basis with good results are wrong?

Instead of trying to decide who has the valid information, look around at what others are doing(stereo mags,stereo shops,soundoffs,etc).I will agree most factory charging systems are not capable of large aftermarket current draws, but the picture isn't quite as grim as GTM paints it.My apologies to the thread starter, I always seem to get in stupid arguments in other peoples threads.

 

[LightningGSX]

1997 ECLIPSE , what do you mean not connected directly to the battery? You should have a FUSED(within a foot of the battery) power wire of at least 4 gauge(not 8 or 10 like others will tell you) connected directly to the battery.Smaller gauge wire will ultimately draw more current and your amps will produce more heat.Make sure your amps are grounded with a similar size wire.And make sure you add a larger ground to chassis wire on your battery.Add a cap, you will be pleased with the results.

 

[GTM]

Originally posted by LightningGSX
1-I don't know what the link you provided really has to do with anything.

I got this all figured out, there ain't nuttin I write here which you won't try to argue about.

Since there are some 20,000-30,000 cars I've worked on in my life time I'm not about to toss that aside for you telling me to get a multimeter and I don't know anything about electrical systems. Hells bells I designed what in all probability was the first transistor ignition system with no extra moving parts in 1959-60 some 5 years before Dan Gurney ran Indy with one. I have absolutely no desire to keep going round and round with you. Dollars to donuts you couldn't even tell the guy how to do a charging system test in 1-1/2 min.

The snow plow example demonstrated nothing except they probably have a 180 amp alt and have calculated what they need to do which is not closely related to what Dan is trying to do. The blade goes up, the blade goes down driven with an electrical motor which pumps oil to the ram(s). It's not continuous operation unlike Dan's radio. Frankly for a lot less money they could have used the power steering pump and 2 or 3 spool valves for that whole operation and more reliability.

It might be better that I don't install radios and you not fix other people's cars.

The focus was supposed to be on Dan's problem and hopefully I've given him enough info to make some better choices in the future. I'm outta here.

GTM

 

[LightningGSX]

His stereo system current demands are far from continuous, the point about the GM trucks was dual parallel battery setups work flawlessly and have been done for quite some time.They come with 105 amp alternators and some 140 amp units.While you might be quite experienced,its obvious your experience lies outside of what we are talking about.I have clearly shown your figures are exagerated and others have clearly shown stuff I have talked about WORK safely with excellent results.My last post.

 

[1997 Eclipse]

Thanks GTM, Lightning GSX for all the constructive information. This is one of the best reasons to check out the boards and ask fellow DSM's for advice and help. My course of action seems to be as follows

1. Engine grounding wires as per the following DSMTuners Tech Articles:

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=75889

2. New alternator-battery cables.
3. High performance positive battery terminal.
4. connect Stereo directly with 4 gauge wire (Lightning Audio)
5. Conserve power by using Stereo mainly during the day time.
6. upgrade battery from 70Amp 600CCA AC Delco to a 80Amp, 700CCA Diehard International.

Anyother suggestions or comments would be highly appreciated.

Dan

 

[GTM]

Originally posted by 1997 Eclipse
Thanks GTM, Lightning GSX for all the constructive information. This is one of the best reasons to check out the boards and ask fellow DSM's for advice and help.

My course of action seems to be as follows

1. Engine grounding wires as per the following DSMTuners Tech Articles:

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=75889

2. New alternator-battery cables.
3. High performance positive battery terminal.
4. connect Stereo directly with 4 gauge wire (Lightning Audio)
5. Conserve power by using Stereo mainly during the day time.
6. upgrade battery from 70Amp 600CCA AC Delco to a 80Amp, 700CCA Diehard International.

Anyother suggestions or comments would be highly appreciated.
Dan

Comusta Dan:

Pa anno sasa bien mo, mabute?

You are welcome.
All of that looks pretty good and makes sense. You might ask Delco what might happen with the 80 amp if you subject it to 100 amp continuous draw. Batteries get hot charging and discharging, this can cause the plates to warp and evenutally short out with each other. The results are you end up with less than rated specs and even more heat.

Ham radio operators will add a couple flat braided ground straps to the hood and trunk and only 1 for each door because they are on the vertical plane. You might also consider lightning grounding straps though I don't see them much any more. The flat braid has gotten pretty expensive these days so if you are in a pick your part type wrecking yard look for earlier VW bodies and bag them when you can find them. The advantages of the flat braid is the surface area vs winding into a tight spiral.

There has been mention of "marine" batteries, in theory they are supposed to be a deep cycle... meaning they can be discharged to a lower potential and then recharged at a faster rate initially and then a normal tapering charge. An alternate source are "golf cart" batteries but you may find these are more likely to be 6v rather than the 12v but the industry may have all switched to the 12v system from a cost standpoint. However if you are running them in parallel you could have a charge rate issue with 1 battery taking a greater charge and thus overheating.

I lived 41' world class IOR sailboat for 23 years, and raised 2 kid. I used D8 and D4 batteries plus 2 only for engine and generators. Needless to say more than one way to charge anything through a variety of switches and relays but always isolaters on everything. If you have ever seen a Marine survey report it always includes information about battery isolators. You can't call AAA for a jump start when you are 500 miles offshore.

Feel free to email me with any questions.

Cheers,
Gene

 

[1997 Eclipse]

Thanks Gene,

By the Tagalog, you are a Fil-Am or have spent time in the Philippines. I am an Australian who have lived in the Philippines for over seven years and probably many more to come. If you are ever in the Philippines, please catch up. Three of us started a Eclipse Club in the Philippines about six month ago and have about 20 members (out of a total of less than 100 Eclipses). We have about 10 - 15 regularly turning up to meetings twice a month.

Another question, I am about to rewire my fuel pump with larger gauge wire and direct to the battery. As I am rewiring my stereo with 4 gauge from the battery to a Lightning Audio Fuseblock, with 8 gauge going to my amp. Can I rewire my fuel pump with 8 gauge directly to this fuse box or should I go to the battery.

Salamat.

Dan

 

[LightningGSX]

I wasn't going to post again, but I had to.You old school car guy's kill me.You speak of your credentials and your experience yet you've clearly posted incorrect and out of date information.While these issues you speak of might have been problems in the 70s or 80s they are NOT in the modern automotive world.Your comment on the charging voltages, you shouldn't have to test vehicles because you have lots of experience?You must have forgotten a lot.I challenge you or anyone else to take a multimeter to a significant amout of vehicles and not come up with a calculated average of around 13.8 volts.Since you resulted to attacks on my intelligence above, you must have realized you couldn't dispute my info.The comment on ground straps? ground straps are at best a cost effective measure on the part of OEM's and are inferior to actual cable.your info is easily disputed and for the most part wrong(not to mention you don't even know the very simple watt/amp/volt calculation).You should stick with carburators and gear driven distributors, because technology has clearly went around you.I have rock solid experience in modern electrical systems and stereo installs(10+ years) and I have not posted ANY incorrect info.1997 eclipse run your new fuel pump relay directly to the battery.Use the factory fuel pump trigger wire to run the new relay.

 

[GTM]

Originally posted by 1997 Eclipse
Thanks Gene,

By the Tagalog, you are a Fil-Am or have spent time in the Philippines.

...........................
None of the above, my wife of 30 year was born in St. Anna, Pampanga and we met here state side. Do have some Australian relatives on her side.
...........................

If you are ever in the Philippines, please catch up. Three of us started a Eclipse Club in the Philippines about six month ago and have about 20 members (out of a total of less than 100 Eclipses). We have about 10 - 15 regularly turning up to meetings twice a month.

.......................
Thank you for the offer, I've never been and our plans to spend a couple of years cruising the islands changed when the kids came along. We sold the boat 3 years ago and now land locked.
....................

Another question, I am about to rewire my fuel pump with larger gauge wire and direct to the battery. As I am rewiring my stereo with 4 gauge from the battery to a Lightning Audio Fuseblock, with 8 gauge going to my amp. Can I rewire my fuel pump with 8 gauge directly to this fuse box or should I go to the battery.


..............................
I see no problem with what you propose as long as the pump is only on when the key is on. I will qualify that with not knowing the load capacity of the proposed #4 wire not having any significant voltage drop. You could put a voltmeter on the pump wire and monitor it for a few days just to make sure everything is ok.
............................

Salamat.

Ikaw

GTM



Dan

 

[GTM]

Originally posted by LightningGSX
I wasn't going to post again, but I had to.


I've looked at several other threads where you have put in an appearance and notice a tendency to have a snot nose attitude bordering on enticing flame wars.


Get a youself an engeneering hand book and read it. Then quote version, chapter and page when you want to take me to task ever again.

I do no believe this is the forum nor the thread to keep having you pop up and try to show us your superior knowledge as a manifestation of who knows what...

Go start your own thread, take surveys, when it's all over write a book on etiquette.

In all your posts I've only found one thing to be remotely true... it is possible to become persona non grata very quickly.

As far as I'm concerned this will not continue. Hope I've made my self perfectly clear or do I need to quote e.e. cummings.

GTM