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electrical problem

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ianGST

15+ Year Contributor
51
0
Apr 29, 2004
Fort Worth, Texas
I recently did a head gasket and timing belt job on my 97 GS-T. Now, for some reason, it seems my battery can't hold a charge for very long. I replaced it with a new battery and its doing the same thing. As I drive, the lights get dimmer and dimmer until eventually the speedometer and radio stop working. Driving faster recharges things a bit, but only until I park. It is also having a hard time starting (though this is probably just because its an old starter and the battery is going through some abuse). Also, I only drive the car once a week, if that, so maybe there is a small electrical drain taking its toll over that time period?

Any ideas would be greatly appreciated. Thanks!

:dsm:
 
I would say it could be a small drain somewhere. Could be a bad connection or ground on the alt. or battery terminals.

Have you had your alt. checked to make sure it isn't just going out as well. Could be just some random bad luck that it's going directly after getting those other parts replaced.

Mike
 
Thanks phantomhp. The car has a new battery and new alternator, so it must be a device drain or shortage somewhere. I've been compiling a list of things to check (from other posts) and have this so far:

1) main battery ground
2) battery shorting on hood
3) frayed battery wire
4) frayed alternator wire
5) blown alternator fuse
6) the fact that my license plate bulb burned out a while ago..?

Any other ideas would be great!

:dsm:

Edit: Where are the common grounding wires that come off the wiring harness? I can't remember taking any off when I had the head off.
 
ianGST said:
As I drive, the lights get dimmer and dimmer until eventually the speedometer and radio stop working.
This sounds more like a bad alt, alt fuse, or poor alt connections (could possibly be bad battery also). Just because you have a new alt and battery don't discount them. I have seen too many "new" alts and batteries that have been bad. Almost all "new" alts are really rebuilt ones that come with varying quality. If you really have a drain it might be in the alt itself even. Alts can only be tested properly at alt and starter repair shops - NEVER at an auto store. What is the voltage at the battery terminals at idle and at 3000 rpm with your lights on and off? If it's not over 14V you have a problem.

If you really suspect a drain see here: http://www.dsmtuners.com/forums/showthread.php?p=1496998#post1496998 and do the test light trick. If it goes on (short), disconnect the alt (tape up wires) to see if that's the drain. If short but not alt follow suggestions in article.
 
Thanks for the help guys. I went out to the car today with a nice technical list of stuff to check. Obviously I checked the easiest thing first, and after a whole 2.3 seconds noticed that the wire connector to the negative battery terminal post was cracked. Completely. It still made contact, but it was loose enough that I imagine it could slip up and possibly temporarily off if I went over a bump. Anyway, I replaced it with one of the dozen or so I had lying around and, of course, the battery was dead. I'll jump it or bring the battery to AutoZone next time I'm out there, but do you guys think this faulty ground was the source of my problem or not?

Thanks!
Ian
 
luv2rallye said:
...
Alts can only be tested properly at alt and starter repair shops - NEVER at an auto store.
...

Geepers I'm flabbergasted, how can you say that with a straight face.:(

Any _certified_ NIASE (ASE) Master Mechanic should be skilled enough to properly diagnose and repair starters, alternators, read schematics and just about any other component with simple miniature circuits including instrument clusters. They should be able to repair instrument and switch printed circuits as well. In this case the alternator can be diagnosed with a test light, DVDM, and an inductive ammeter. The regulator in this case is essentially a current limiting device but since the mfg doesn't consider this repair is within the scope of a skilled mechanic.

Granted getting an EE degree does not include much hands on experience in the automotive industry but then you don't want me designing the North American Power Grid either.

Looks like I'm going to quit procrastinating and write a simple how-to test and diagnose an alternator.
.........................

ianGST I am guessing the ground you found broken is part of a dedicated circuit that involves the alternator regulator and possible the ECU. Because they don't want spurious radiation from relays and spark coils they include this in the harness. I don't have a schematic for your car but on the 1G that same ground would have also connected to the OBD port and might have been found when trying to get readings.

Hopefully when you make repairs to this wire you will find you are charging at 13.8 -14.2volts.

Cheers,
GTM
 
GTM said:
Geepers I'm flabbergasted, how can you say that with a straight face.:(

Any _certified_ NIASE (ASE) Master Mechanic should be skilled enough to properly diagnose and repair starters, alternators...
Ok, sorry, yes for sure. I should have just said don't take it to an auto store for testing. Many, many people on here who have alt problems take their alt to an auto store to have it tested for free rather than pay a ASE certified mechanic. My only point is that auto stores do very poor and incomplete testing. To properly and completely test an alternator it should be brought in to an alternator/starter specialty shop - not an auto store which only tests go/no go output voltage. The alt shop will test for too high AC voltage, max current draw, bad diodes/regulator, thermal, short protection, low & hi speed operation, current drain while spinning and not, bad bearings/brushes, and a dozen other things which no auto store can/will do. And all this is usually for free. Also they are the experts since that is their specialty.
GTM said:
Looks like I'm going to quit procrastinating and write a simple how-to test and diagnose an alternator.
Great idea. This is sorely needed and I think everyone will benefit. Go for it and place an article in the Tech Guide Electrical.
 
luv2rallye said:
...
Great idea. This is sorely needed and I think everyone will benefit. Go for it and place an article in the Tech Guide Electrical.

Okay, it's done and in the electrical section under:

2 minute alternator circuit test.

This is a basic test to see if the alternator is able and will charge. This is as fool proof as they come and are absolutes. It however is not intended to establish if there are bad brushes, burned/shorted diodes, open/shorted windings etc only that it is charging some amount.

The idea is to prevent so many DIY from misdiagnosing alternators as being bad only to find they have a 25¢ fuse burned and spent $100-$200 for an alternator they didn't need.

Cheers,
GTM
 
Okay, I replaced the main battery ground that connects the negative terminal to the car because it was cracked in half. I also went and got the battery charged, but it only went to 450 of 525 CCA after being there for an hour. I set my turbo-timer (don't know how accurate these are..?) to read the battery voltage. After ten minutes of driving it seemed to be at a stable 12.8-13.5V at idle and 13.5-14.Vunder spirited driving. At idle with every electrical thing I could think of running (ac, lights, radio, wipers, etc.) the lowest it got was about 11.0V when it spiked, then jumped back up to 12.3-13.0V.

The car is NOT currently doing the problem with the radio turning off and speedometer cutting out, but thats to be expected until the battery gets low again. Any comments? Is that about right for the voltage or should I go ahead and do a more accurate test? The car also has a really hard time starting, but the battery is obviously questionable and the starter hasn't been replaced since I've own the car.

Thanks for the input!
 
ianGST said:
...
After ten minutes of driving it seemed to be at a stable 12.8-13.5V at idle and 13.5-14.Vunder spirited driving. At idle with every electrical thing I could think of running (ac, lights, radio, wipers, etc.) the lowest it got was about 11.0V when it spiked, then jumped back up to 12.3-13.0V.

The car is NOT currently doing the problem with the radio turning off and speedometer cutting out, but thats to be expected until the battery gets low again. Any comments? Is that about right for the voltage or should I go ahead and do a more accurate test? The car also has a really hard time starting, but the battery is obviously questionable and the starter hasn't been replaced since I've own the car.
Thanks for the input!

The voltage seems to be a bit on the low side unless your voltmeter is low, you should be seeing 13.8-14.2 charging at all times.

A good fully charged battery should be 13.2 and never 11.0. If you have the 4 wire plug and internal regulator on the back of the Alternator 2 of the leads go to the ECM but I'm not clear on how this influences the regulator. There are 2 other relays involved with the field windings with one having a diode in the coil windings. Should this diode be shorting or causing an open circuit you will then loose power to the field (brushes and comutator) but you have to catch it in the act.

Oh, Have you checked for any error codes?? The 4 wire system does monitor the input as part of the ECM. I've never seen a 4 wire system so working purely off schematics and the little I've learned. I may never have a quick diagnostic test because there is too much going on. May be able to conclude it's the Alt or the ECM but that's not good enough.

Why did you change the Alt. was it for the same reasons??? This may point to the ECM or other related component such as a transmission switch.

Cheers,
GTM
 
I'll look into the alternator wires when I'm at the car next. The only error code I get is an annoying fuel pressure solenoid one that I've gotten since I can remember, but I'll check again because I haven't checked since I put the charged battery in and drove it around. I changed the alternator because it seemed to sit at a funny angle, and eventually started making a strange "rubbing" noise because of it. The new alternator is warrantied by O'Reilly's so it really isn't a big deal to get another one, if I have to.

By the way, I noticied that the water seemed to have "boiled over" very slightly when I took the battery to get it charged. Also, the positive terminal connector seems to have been overtightened a little bit and has a very small crack in it. Not nearly as cracked as the negative was, but probably something worth changing, right?

Thanks for the help GTM!
 
ianGST said:
...
By the way, I noticied that the water seemed to have "boiled over" very slightly when I took the battery to get it charged. Also, the positive terminal connector seems to have been overtightened a little bit and has a very small crack in it. Not nearly as cracked as the negative was, but probably something worth changing, right?

Thanks for the help GTM!

Hmmmm, how old is the battery? Any accidents with it? I dismissed the CCAs you had posted earlier because it was a 1 hour charge rather than overnight.

Now you mention the boiling raises an eyeborw, if you can pull the caps off the battery and look inside the electrolite might be low on 1 or more cells. This could be from a defective battery or charging system. I'm wondering if you might have some broken or loose plates or the internal straps connecting cells are loose.

Let me explain that as long as the caps are on the battery any Hydrogen gas is in such concentration that any internal arc inside the battery will not normally cause an explosion. When you pull the caps off now some escapes and air comes in and then can blow up. I've seen this with co-workers, I've had it happen so use care, disconnect ground before removing caps, always stand to the side when removing and installing cables and never with the caps off.


With the caps off you can check the electrolyte specific gravity and charge state with an inexpensive ($4) tool which has several small plastic colored balls that float in the acid. None of the above has to be true, sitll it could explain some of the problems that have been happening.
..............

You can buy brass/bronze replacement battery cable terminals which can replace the damaged end. They "ain't". cheap at $4-$7 but will outlast the car. If you have sulphates growing inside the cable insulation and you have enough length you can clean with a power wire brush the strands after you skin back some of the insulation.


Keep us advised and you are welcome.

Cheers,
GTM
 
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