Alternator Output Problems.

[liquidloot]

Well, i've been messing around all week trying to fix my car. Damn electrical problems.

Well my car hasent been able to keep a charge all week. I replaced my alternator last week, and the battery is fine. I cleaned the terminals, replaced the fuse, nothing worked so far. Ok well i get my alternator tested at autozone. The guy says according to his little machine I'm not getting any output from the alternator, and he said according to the machine its becuase theres a fualty wire or connection somewhere, so i check my connections, looks fine to me. So i'm thinking of replacing the whole wire all together if no one has any other suggestions.

Can anyone steer me in the right direction in order to do this job? Where could i find a new wire/connectors to replace the output wire.

Thanks :X

 

[Shadow98]

Ok, i'm a little confused here. The only thing the machine in AutoZone does is say if the part works or not. If there is an O'reilys by where you live, take it to them and have them test it. They can tell how much power it's putting out. Only other thing I can think of would be your wiring to and from the alternator.

 

[AK_4g63t]

True. If your alternator has a belt on it and it's new, it works. So the only other thing it could be is the wiring. Double check it again. Sometimes they do corrode and sometimes it's in the insulator so you can't see it. This will cause the power to not pass through the wire. That could very well be the issue. You can use a multimeter to see if the wire is pulling high resistance, this will let you know if corrosion or an open in the wire is the problem.
-Donny
*you can buy a cheap multimeter for $20 at walmart, it's worth it and a great tool to get used to using.

 

[Beanokid69]

what should the resistance be at normally?

 

[perley03]

what should the resistance be at normally?

0.00 or ∞, depending on the meter. Basically there should be zero resistance.

 

[Beanokid69]

are you sure because the average resistance on the ecu wiring is like 12ohms or something like that I dont remember. maybe it was 1.2 but anyway it wasnt 0

 

[Linkizunlistd]

Can someone post pics on the wires to look at because i am having the same issue. If I can avoid replacing my alternator by replacing these wires I would like to do that. Or if need be both might need to be replaced.

 

[timot]

The guy says according to his little machine I'm not getting any output from the alternator, and he said according to the machine its becuase theres a fualty wire or connection somewhere, so i check my connections, looks fine to me.

Thanks :X

That would mean it is something internal in your alternator...don't trust those fools honestly, they aren't ASE certified, and if they are it is for parts only, take your alt somewhere or check it's voltage output on your own, then post back up, and I can help you

 

[Defiant]

True. If your alternator has a belt on it and it's new, it works.

Not necessarily. "New" alternators (undoubtedly a rebuilt) also fail. With irritating regularity.

 

[Talesin]

Agreed, I got a dead one out of the box before.
Don't rely on their meter, get your own and test the output at the B+ bolt on the alt. With every power-draining device you can think of turned on (high beams, interior fan, stereo up high, air conditioning on, etc) it should be charging at no less than 13.5V, though a momentary drop is OK (internal regulator needs to switch it on and adjust the charging level).
If the charging level is too low, take it back. You'll just kill your battery, undercharging.

 

[Detail]

As posted elsewhere I'm having similar problems. I'm up to 11 remanned (7 advanced auto, 4 from o'reily) in the last year and half. I've also lost 2 optima red tops during that time do to over/undercharging with one completely letting go and putting acid everywhere in the corner where teh battery sits. You should see the DSM sticker...all mangled.

Anywho, last night I changed the alternator and tested the battery at O'reily. Battery fine, alternator done...as usual. Also, I pulled back the wire harness for the plug all the way to about half way behind the radiator. No splits...grounds, good to go. Cut the plug off just to be sure. Soddered (spelling?) in a new(er) plug off a galant from the Junk yard that I pulled yesterday as well. tapped everything back up and tested. Worked fine. 13.5 v with everything off. 13.5v with lights on and such. Drove great last night. Wake up this morning. Start driving to work. I'm watching voltage off my blitz fatt turbo timer. Voltage is spiking from 13.5 to 14.9. 3/4 of the way to work it settles down to 13.3 or so. I'm at my wits end with this crap. I'm a pro at pulling the thing out but would rather not be. I'd like to just drive my car and not think about things like this. This is what makes DSM guys sell a really nice car for like 2k. Anyways, what do you guys think I should do now? I posted up yesterday asking if anyone had tried an external regulator (bosch setup from Napa). Or I've even thought of the high output one from the place everyone suggests on here. Only thing about that is that with as much trouble as I've been having I can't afford (literally) the downtime to ship a bad one back to get another.

HELP ME...I'm dieing here.

Here is my other post about the issue with some interesting notes/link

http://www.dsmtuners.com/forums/showthread.php?t=192448

 

[weldtuner]

The problem with remanned alternators is they only replace what needs to be, or what was fried. When they check your alternator at Autozone they are just spining it to see if it reads 13.5v or more, they do not check them under a load which was what talesin was talking about. I went through 3 alterantors that checked out fine at advanced auto and as soon as I put a load on it would stop charging. You may want to check the resistance from your alternator case to the ground cable of the battery, shouldnt be any more than 1 or 2 ohms.

 

[Detail]

Pulled the OEM manual out last night. There is an alternator relay on the 2g. It's located next to the stock boost controller on the the frame rail by the overflow bottle. I'm going to try a few things next.

1)Wire a 4guage wire from battery to alternator outside of harness to test. If successful:
Pull the radiator/fans out. Pull the whole harness out to the battery. Remove the ground cable and install a 4 guage one there.

2)Change the relay

3)Change the 100 amp fuse

4)Probably going to go get another (number 13) alternator and try it again after that

Voltage in the car right now is like a sine wave under load. It goes from 13.5v to as high as 15.2v according the turbo timers voltage reader. Lights everywhere dim and brighten as I drive.

This can't be good for the rest of the electrical system.

Update to my issue:
I haven't done anything that I said I was going to do above, yet. I've been busy working. Anyways, on the way home last night bizarre things started happening.

First 20 mins of drive voltage is all over the place from 13.5v to 16v.

After around 25 minutes of driving things mellowed out and the car acted properly charging at 13.5v at idle. A I reved the motor the voltage slowly increased. How is it that the stuipd alternator is pushing out crazy unstable voltage but after a certain period of driving (maybe once it gets hot) that it starts functioning as its supposed to???

 

[luv2rallye]

Detail: See here about the alternator (generator) relay: http://www.dsmtuners.com/forums/showthread.php?p=151082118#post151081889. Since the alt is putting out I doubt that's your problem. With all the alts your going thru I would suspect a short that's burning them out. How to test for shorts: http://www.dsmtuners.com/forums/showthread.php?p=1496998#post1496998. BTW normal charging voltage is 13.9-14.9V at 68F. The car's elctrical system can handle 16V but that high a voltage will burn out your battery and the alt shouldn't be that high.

 

[Detail]

Thanks for the links, hadn't seen those as of yet. I'll go through and test as much as possible this weekend.

Update:
Changed the fuseable link, still no better.

 

[moto x]

resistance should be .05 or less on the b+ side and like .03 or lower on ground side

 

[fhudsonjr]

When you change out your alt. be sure your battery has a full charge.
Putting in an alt. w/o a fully charged battery can cause the alt. to go bad.

 

[Talesin]

When you change out your alt. be sure your battery has a full charge.
Putting in an alt. w/o a fully charged battery can cause the alt. to go bad.

Wait... what?
A dead battery (will not accept a charge) could theoretically kill the alt, as it would have to keep switching on constantly to handle short-term peaks. But as long as it can take a charge, it should re-charge again under normal use and be just fine, no matter how low it was when the alt was swapped.

 

[Detail]

The battery is fully charged. I have the whole front end fileted apart right now. I pulled the whole stinking harness out to look for damages to the wiring. I'm also going to go ahead and upgrade the size of the power wire running from the alternator to the 100 amp fuse and then on to the battery. How big is too big? I dont' want the alternator to kill itself trying to push voltage over an enormous line. I'm thinking 4 guage. Anyone have any experience with this?

I'll be testing the 4 plug wires this evening.

Anyone have a clue how to replace the alternator relay if it is indeed bad? It doesn't look like a normal relay.

 

[Detail]

Nevmind, just read your second link...good read.

 

[always_broken]

Here's a tip. Instead of the double wires coming from each post on the alternator fuse, I used a 8 gauge 24" wire with the correct ends. Clears up a little is more secure.

 

[Detail]

Rocking 4 guage as of right now.

 

[luv2rallye]

How big is too big? I dont' want the alternator to kill itself trying to push voltage over an enormous line.

Sorry and no offense but I just had to laugh. You obviously have little experience with electricity so it's not your fault (and so please don't take any offense or feel bad as I understand your comment and why you might say that with your experience) but that's quite good for a laugh for those who do know about electricity. It just so funny I had to let you in on it. So you can get the joke: Alternators cannot kill themselves no matter what size the wire is. It's the size of the load on the wire (current draw) that can kill an alternator if it's too much. The wire just transfers the current to the load and the less resistance in the wire the less voltage drop will occur over that wire (which you want at minimum so more voltage will get to the load). And wire resistance decreases with size so actually the larger the wire the better (which is why some use 4 gauge - the lower the gauge number the bigger the wire). Also alternators push current not voltage through wires. Electricity flowing through wires is like water flowing through pipes - the electrical current is the water and the voltage is the water pressure and of course the wire is the pipe. The amount of current the alternator puts out will always be only the amount the load needs (up to the alt's max rating) and no more. Alternators also have regulators in them to keep the voltage constant no matter what the load (up to max current rating) and also to prevent the alt from burning itself up trying to put out more current than it's rated for (for too much load or shorts).

The stock alt wires to battery positive are two 10 gauge wires in parallel which is equivalent to one 7 gauge wire. So 4 gauge would be fine (or two 8 gauge which is equivalent to one 5 gauge).

 

[Detail]

Speaking of that relay in the above link, does anyone know what resistance should be seen across it? It's pined out really weird. I'm basically seeing it as a wide open "relay"

 

[luv2rallye]

The resistance of the generator relay is meaningless since it is a non-linear device (diode in series with a resistor). Using an ohmmeter you should read infinate in one direction and could get anything in the other depending on the output voltage of the ohmmeter on the scale you're using (every scale is different). A non-linear device has different resistance for different voltages applied (and it's not proportional) so you will get a different reading on different scales, if any at all. You also will need an output voltage more than about 0.3V to even get the diode to partially turn on which is usually on the lower scales. And even then the series resistor may be so high a value that on those lower scales you may read nothing. So if you get infinate in one direction and anything in the other it's probably good. On the other hand you may read infinate in both directions when it's either good or bad - you can't really tell with an ohmmeter. There's no good way to test it unless maybe you removed the dash alternator charge lamp and see if the alt is still putting out with the engine running.