Stalling Issue, Electrical Problem

[Snobordin8]

My car has been giving me trouble lately. At first the idle would drop to about 650 when I turned the lights, blinkers, fan, etc. on. The lights would dim as the blinker blinked. I figured the alternator was bad. I tested (with a multimeter) it at 15v output from the alternator and 15v at the battery while running. The battery showed about 12.5v when the car was not running, and just a hair less with accessories on, so that checked out.

Then randomly when driving the car, usually when at idle, the car will randomly die. All the gauges drop and my abs light and check engine light kept coming on. Sometimes it will fire right back up and everything will be normal, and the gauge lights will go away. Other times I lose power to my afc, gauges, lights, blinkers. Weird thing is is that when this happens my power seat still works and interior lights work as well as the light that tells me my door is open. It does nothing when I turn the key. I let it sit for a few minutes and it'll fire back up, then usually right down the road it will repeat. My car has had the abs removed.

I swapped out the batteries with one I use in my DD so I know it's not the battery. Any ideas would be greatly appreciated.

Edit: I put new terminals on and cleaned the posts to insure good contact.

 

[grnchevyz]

That does sound like alternator to me...maybe just a loose wire. I had this issue and for me it was the wire to the fuse box that was loose. Changed the connector, changed the screw and it solved my problem.

Of course, I blew the alternator the following week but that was another issue - 6000w of power didn't agree with mt stock alt

Hope this helps.

 

[Snobordin8]

I checked the wire at the fuse box and it looked like it was in great shape, didn't wiggle or have any corrosion on it. It's just weird when the car dies some things still work, while the ignition, afc, headlights, gauges, and heater won't. Thanks though.

I just realized that there are two wires running from the alternator output to the fuse box, and two from there to the battery, I've heard of that mod before but just found out my car has it.

 

[Snobordin8]

Okay I just ordered a logger, as I don't have one now (I know I should've had one before now, please don't hassle me). Hopefully the code it's throwing will point me in the right direction. I still have no clue what to do.

I have the B&M FPR, which I have heard bad things about. Would running too much fuel cause symptoms like this?

 

[Snobordin8]

I got my logger not long after my last post and the CEL ended up being P0505(Idle Control System malfunction). I had an extra ISC on my other DSM so I swapped them out. I didn't even reset the CEL, it just went away. Well now the car quit doing it's random dying, and it has started to idle better (right around 950-1000).

I thought I was in the clear and then the same code got thrown again yesterday .

Another thing the car is doing is somehow it is not being able to start on its own, it always needs a little help from the charger if the car has been sitting for more than about 24 hours. Something is draining the battery it seems.

I checked the voltage again of the alternator and here is what I got:
-At battery, car off=16v
-At battery, car on=18.3v
-At output of alternator=18.8v
-At battery,all accessories on,car on-15.8v
-At alternator,all accessories on,car on-16.8v

What could be causing these high numbers? (I checked with a multimeter) I jumped the car earlier, I didn't think to check the volts at the battery before I jumped it.

Any ideas?

Edit: I just checked the resistance between the coils on the ISC and they have about 32 ohms resistance, which is okay. And I am dumb, I thought I had changed the ISC when in reality I changed the TPS, probably why it threw the code again.

 

[phreak965]

i'm almost positive that those high numbers are coming from your voltage regulator gone bad..take your car to an electrical shop and they should rebuild your alt. and you'll be fine

 

[redline2k6]

also any autozone or shop like that offers free alternator testing i agree with phreak965 it could very well be the votlage regulator or an internal diode in the alternator the test should show what the problem is