About a month ago, my battery light started wacking out and flashing sporadically while accellerating. It started getting worse, to the point where I couldn't accellerate because it would start to die, and all the lights and stuff would go out while acellerating too. Took it in, they said the alternator was bad. Got it replaced. Fixed the problem. Now, about 3 weeks after getting a *brand new, not refurbished* alternator put in, I am having the same problem again! I am guessing it's some sort of electrical system problem, a short or somthing draining the system really fast.

How do you check for electrical problems? Can I find it myself do you think? Any suggestions will help....thanks!

 

Before starting you would need 2 things, wiring diagram and a DMM (digital multi meter). Both can be bought from the local automotive supply store.

 

I have the Haynes manual, which has all the wiring diagrams, and I'm borrowing a DMM from a friend. Now I am wondering where are the first places to check for problems, and how to spot a problem. For one, where should I hook up the DMM to check if the alternator is charging correctly?

 

First thing you should check is the voltage the battery is putting out.I may be wrong about this, but I think all alternators are remanufactured. It could still be the alternator. You should check all wires connected to the alternator and make sure they have a good connection. Check the battery ground cable and make sure it's nice and tight and make sure the other end isn't loose.

 

Battery voltage should be 12V, right? Is there a way to check how much actual potential charge is left on a car battery? I think it's just really really low...what's the best way to check the charge, then charge it, if needed?

 

U're right. Batt voltage should be (actually...) a little over 12V (like 12.6 or so). then once the car is started voltage should jump to about 13.5 (+/- 0.5). But given that the car starts the battery shouldn't be the problem.

My recommendation: If possible return the alternator and give another one a shot. (bad alternator, slight possibility)

If problem persists, first start checking the major wires (Batt+, Starter+, pretty much anything in the engine compartment) for anything that may have rubbed a manifold or something and got its skin melted (simultaneously check for any breaks in these wires). After that, check to see what electronic device stays on after key is removed, or to see if any device suddenly stopped working/started acting funny over the last few days/weeks (don't leave out the small stuff: check bulbs and crap like that too). If u have a stereo disconnect it temporarily (at the batt) to make sure it hasn't screwed up anything.

*stuff in the gauge cluster USUALLY isn't the problem so u could skip tearing down your dash, initially*

Also check to make sure your plug wires aren't sending jolts of current to your ground as it could possibly feed through something else before going to ground, screwing up something else, causing the short blah, blah, blah. U get the point.

For now do these basic checks and see what u come up with. If that doesn't work then it's time to kiss sanity goodbye and either spend some bucks buying a short-finder or carry it to a electronically inclined mechanic (who will probably charge u out your a**).

Welcome to the world of electrical gremlins....
*insert evil sinister laugh here*

 

I went through 2 remans and a new alternator before I got a good one for my GMC Jimmy. Some batches are just bad I guess.

Pete