Need some help
Thread Starter
Instructor
Joined: Apr 2013
Posts: 222
Likes: 3
From: Ottawa Ontario
Need some help
So I got my supercharged 96 back from the shop yesterday, if had a blown motor and get it replaced and they had told me the alternater hadnt been working, i had the car running and when I opened the door it had stalled iut anf wouldnt start again, im thinking it is a bad ground somewhere, so i was curious on some info on ground G101, G102, G107 and G106, they look to be the most plausable grounds possibly at fault.. Any info or pics pf these grounds or any other opinions maybe on a possible different problem!?
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
If you run the car and turn your lights on, does it stall? It could be a bad ground wire for something ignition or fuel related, but if it stalls when you turn on the lights then I would look more towards the alternator.
Thread Starter
Instructor
Joined: Apr 2013
Posts: 222
Likes: 3
From: Ottawa Ontario
well yesterday I had my fogs on and all the normal dash lights, then when I opened the door to get out the dome and door lights came on it died. I feel like it is both lmfao :P I went to move it last night after jump starting it and i moved it about 25feet and it stalled out again.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
If the shop said "the alternator hadn't been working" did they test it or replace it? A good shop would have brought that to your attention. What is the voltage as shown on the dash digital display with the engine off and the key turned to RUN? And with the engine running?
I would suggest at the minimum, having the alternator and battery tested. Not at the chain parts stores, but go to a reputable shop where they can perform a load test on the battery and check alternator output. A test like this is properly done with the battery in the car, alternator hooked up and the engine running.
It's entirely possible that the shop did not reinstall the various ground cables or didn't tighten the battery ground cable where it attaches to the engine.
One thing you may also check is to watch the displayed voltage when the problem happens again. With the ignition key still at RUN, the display should still show a voltage. What is it?
I would suggest at the minimum, having the alternator and battery tested. Not at the chain parts stores, but go to a reputable shop where they can perform a load test on the battery and check alternator output. A test like this is properly done with the battery in the car, alternator hooked up and the engine running.
It's entirely possible that the shop did not reinstall the various ground cables or didn't tighten the battery ground cable where it attaches to the engine.
One thing you may also check is to watch the displayed voltage when the problem happens again. With the ignition key still at RUN, the display should still show a voltage. What is it?
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
This should be simple...
these ignition systems require so much voltage that they will not fire a spark plug without at least a good 10V AND high amps behind it. A fully charged battery will only run these ignitions at hiway speeds for about 10 minutes...and you can watch the volts drop in 10ths as you drive....
So,
if you apply ANY drain to the system in a low/minimal charge situation, that will be enough to kill the borderline voltage level to the ign system. Mine will drag the idle down 100 rpm if I bottom out the power windows as it pulls the voltage down and the alt tries to kick in briefly to compensate. Any addition load will stall a weak battery IF the ALT is not producing a charge.
The Volt meter should show you what the alt is doing....should show 14+ V after start up...and idle at 13 when normal and some things running....if the gauge shows less than 13 immediately after start up...the regulator or the alt itself is faulty.
As stated, a good shop would have tested and advised regarding the alt condition. Replace it if faulty or trace the wiring issue. Shorts, hot wires grounded out and poor connections can ALL cause this.
As far as your many grounds, none of those matter to the alt. Those are ALL engine control, fuel inj and dash display control grounds. The grounds that you care about for the alt are the one in the plug-in, the battery/frame/block and the block/frame strap by the oil filter. The "bundle" of harness grounds on the block are all ECM and display grounds. Almost each electrical servo or electrical "thing" in a C4 will have its own grounds somewhere near that part. None that I can think of are related to the charging.
Its easy to over-think these things. Get the Alt tested, and replace if necessary. If it comes down to a wiring issue that YOU cannot diagnose yourself, find an 'auto-electric' specialty shop to do that work. They only charge $75 to $90 per hr to trace shorts and harness issues like this. They will ID the problem and allow YOU to do the repairs yourself. I've used auto-elec shops several times and NEVER had to pay more
than $75 (1 hr min) for a proper diagnosis.
Your FSM will guide you thru any tracing of the system that you want to attempt yourself.
these ignition systems require so much voltage that they will not fire a spark plug without at least a good 10V AND high amps behind it. A fully charged battery will only run these ignitions at hiway speeds for about 10 minutes...and you can watch the volts drop in 10ths as you drive....
So,
if you apply ANY drain to the system in a low/minimal charge situation, that will be enough to kill the borderline voltage level to the ign system. Mine will drag the idle down 100 rpm if I bottom out the power windows as it pulls the voltage down and the alt tries to kick in briefly to compensate. Any addition load will stall a weak battery IF the ALT is not producing a charge.
The Volt meter should show you what the alt is doing....should show 14+ V after start up...and idle at 13 when normal and some things running....if the gauge shows less than 13 immediately after start up...the regulator or the alt itself is faulty.
As stated, a good shop would have tested and advised regarding the alt condition. Replace it if faulty or trace the wiring issue. Shorts, hot wires grounded out and poor connections can ALL cause this.
As far as your many grounds, none of those matter to the alt. Those are ALL engine control, fuel inj and dash display control grounds. The grounds that you care about for the alt are the one in the plug-in, the battery/frame/block and the block/frame strap by the oil filter. The "bundle" of harness grounds on the block are all ECM and display grounds. Almost each electrical servo or electrical "thing" in a C4 will have its own grounds somewhere near that part. None that I can think of are related to the charging.
Its easy to over-think these things. Get the Alt tested, and replace if necessary. If it comes down to a wiring issue that YOU cannot diagnose yourself, find an 'auto-electric' specialty shop to do that work. They only charge $75 to $90 per hr to trace shorts and harness issues like this. They will ID the problem and allow YOU to do the repairs yourself. I've used auto-elec shops several times and NEVER had to pay more
than $75 (1 hr min) for a proper diagnosis.
Your FSM will guide you thru any tracing of the system that you want to attempt yourself.
