I have a 90 vert and every time I turn on my running lights/head lights or use the brakes the idle drops to 400 rpms or there about. When I turn them off or left off the brakes the idle goes back to normal. Could the alternator not have enough *** to run all of the exterior lights? Any help would be awsome
Thanx

 

Check to make sure the alternator belt isn't too loose.

 

Isn't this a BAC valve problem? I believe if you put on an electrical load, the idle should blip down and bounce back to normal with the help of the BAC valve.

SEARCH "BAC Valve".

B

 

YES, to the above.

Try this. Warm the engine up fully. Idle it. While idling pull the BAC plug off and see if there is a change in rpms.

IF there is no change, it's possible the BAC isn't working. It won't be a bad BAC but a bad item in the ECU OR pins in the BAC plug pushed back not making contact with the jacks pins when the plug is installed.

 

Thanks guys I'll give it a shot.