Mechanics

CHEVY ALTERNATOR

1998 Chevrolet Monte Carlo

Electrical problem
1998 Chevy Monte Carlo 6 cyl Front Wheel Drive Automatic 140 miles

I have been having problems with the car shutting it self down. The ABS light would come on then the battery light, and then the headlights would dim and remaining dashlight lights would come on and then it would die. If I waited 10 minute or so I could restart it, drive for a few miles and it would happen again. I replaced the battery and alternator and that seemed to fix it for three months but now it is happening again and much quicker. I had the alt bench tested and it puts out 14V, but in the car it is only producing 9V. I checked the computer codes and the only one is, " multiple cylindar misfiring". There is an after market remote car starter installed which is not working properly, when used I will turn the key on and hit the brake and the car will shut off. Other times I will use it and after five minutes of driving it will shut off the car. Could this be the problem and if so how do I remove it?
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NatesChevy
February 15, 2009.



I woulddefinitly remove it. Those and alarms cause more no-start problems than the cars failing. Start by removing the anel under the teering column to gain access to the wiring. You will see the control box, most likely zip-tied in there. Look for any wires that are interrupted by the box, ie; cut wire thet is spliced and now goes to a relay or controller. Remove any interrupting splices and reconnect wires to their original colors. Follow all wires from the control box, they usuallly use blue scotch-locks to tap into wires, cut the wire that has been tapped onto the cars existing wires and tape it off so that it cannot gound out. There will be quite a few wires from the bx, take your time and disconnect them one at a time until all is removed.

Tiny
Jack42
Feb 15, 2009.
I removed the remote starter, making sure all connections were tapped well. Reconnected the battery and started the car. Within a few minutes the Anti-lock light came on which is the first step towards it shutting down. What would be the next step?

Tiny
NatesChevy
Feb 17, 2009.
Get a meter and see what the alt is putting out at the big wire on the back

Tiny
Jack42
Feb 17, 2009.
We removed the alternater and the batteryand had them checked. While they were disconnected a resistance check on the large red cable was 0.03 ohms. The alt worked bench tested fine, the battery was low at 11.54 volts and needed to be recharged. This was done and everything was installed. Once installed a voltage check was done at the battery terminals the reading was 11.99V. The car was then started and a reading was taken at the battery and at the alternater and they both read 11.59V. We monitored the voltage and it was going down slowly, at the end of five minutes it was down to 11.54V.

Tiny
NatesChevy
Feb 18, 2009.
So you have continuity from back of alt to battery. The small red wire on the alt is the " L" circuit. The PCM controls the charging through monitoring this circuit. PCM has the ability to disable the alt from charging. A scan tool is req'd to see if this is happening. Check for voltage at the small wire, should be about 5 volts

Tiny
Jack42
Feb 18, 2009.
What is a scan tool? I only have a multi meter. If we do not have 5 volts what is the next step.

Tiny
NatesChevy
Feb 18, 2009.
A scan tool is what you plug into the cars data port to monitor what the computer is doing. If no power (5 volts) with key on, go to PCM and locate connector C2 and find pin #61 (red wire). If connections are ok and continuity is good to the alt, according to Mitchell the next step is to replace the PCM

Tiny
Jack42
Feb 27, 2009.