Weird electrical issues

[Tsmith]

Replaced my alternator with one from advance auto (I know mhi is better) because my car died while I was driving. Got it in and restarted the vehicle to find out I had spun a rod bearing so figured the motor just got to warm and locked up. Replaced the motor and everything was fine for about three weeks. I have a left front headlamp that did t work so decided to replace it over the last weekend and found that the power wire going to the lamp was melted all the way into the harness. Guy that owned the car before me did the angel eye headlamps on the car. Weird thing is the light comes on when I lock the doors for like 20 seconds but not with the headlamp switch even though I get battery voltage at the lamp connector. When I plug the lamp in the volt drop is .70 volts but it won't turn on.

Anyways two days ago I was driving and noticed my radio cut out. I looked down at my turbo timer (set on battery voltage) to see 9.48 volts. Shortly after that the headlights dimmed and car shut down completely while driving. Jumped the car and charged the battery long enough to get it back to advance. Battery test showed the obvious bad battery so I replaced it with an optima red top. Charging system checked out ok and went on my merry way. By 2 pm after only driving the vehicle a couple times short distances I saw my voltage dropping again. 9.7 volts when I pulled into a parking spot at the company. Figured I would need a jump again so a couple hours later took a friend out to help. Car started normally and showed 11 volts. Let it idle for a while and watched the voltage slowly drop.

Back to advance again for a charging test showed it was charging fine. I replaced the positive terminal end because it wiggled a bit and didn't want to use a shim. Took off and reinstalled my alternator wires just to make sure. Still having the same issue today.

My questions:
I know the alternator is either not putting out correct amps or is bad internally or possible bad wiring from alt to battery so gonna bench test it today. Any thoughts?

Is the headlamp wiring causing an issue? The parasitic drain was .02 volts.

Anything else you guys can think of?

 

[kayosfrawg]

To me I think the headlights, had something similar on my car with the C2DI the guy had wired a line that was supposed to go to switched 12V into a constant 12 so the caps in the C2DI were constantly pulling juice from the Battery even when the car was off. Anything after market is what I'd check first, especially with melted wires which should be replaced ASAP.

 

[RedTalonTsi]

I have a similar issue, unknown vampiric drain when the car is off. Never had an issue like this in the 10 years I have owned the car. Wondering if anyone has some advice on where/how to start my search for this extremely annoying problem. What is C2DI?

 

[kayosfrawg]

AEM's capacitive discharge ignition, I ended up pulling it til I get the time to go fix the wiring properly right now I'm focused on the rear end damage from the asshat that hit me a few months ago.

 

[RedTalonTsi]

After some more digging found this very useful post: http://www.dsmtuners.com/forums/art...inding-short-partial-short-battery-drain.html

Hopefully it is helpful to others looking here, I know it gives me a place to start.

 

[Tsmith]

Well after replacing fuses, relays, battery cables and ends, checking all connections and three "in car" alternator tests, I finally have my solution. I took the alternator out and into the same advance auto that told me three times my alternator was good and had it bench tested. The damn thing wouldn't even pass the preliminary tests and the machine never even spun the pulley. With a huge grin I had the alternator e banged under the warranty which was only 4 weeks old. Put the new one in and fired up the car to find my voltmeter on the turbo timer at a steady 13.3 volts. After twenty minutes at idle I was at 12.7 volts so I decided to drive the car with fingers crossed. Been driving since then and voltmeter shows 12.7 volts after two hours of running errands. Looks like I am in the market for another mhi alternator to put in in the next 4 weeks or so.

Only reason I didn't start with this is the headlamp wiring being screwed up and the in car test showing a charging alternator. Recommend if you are having issues to have your alternator bench tested to get a true result. Yea it's a pain doing 2 hours of work for something that may not help you in the end but saved me having to ask a stranger every time I stopped to hook up and charge my battery for 20 minutes so I could get to my next destination.