Hello, I just recently bought a 91 CRX Si with the blown original A6 in it and swapped in a Z6. The new engine runs and drives great.... until I turn on the headlights. The car will bog and die, the temp gage will go all the way up, and the tach will stop working. After this happens the car will not even crank over, the fuel pump is not engaging and dash lights will stay lit with the key out of the ignition. If i hit the brake all the lights flicker and the locks click in the door. Once I allow the car to sit over night it will usually fire right up no problems. Sometimes I am able to turn the headlights on with no issues and the car runs perfect headlights on or not. It is an intermittent problem. I have cleaned every ground on the car, checked over as much wiring i can get to for short and replaced my main relay with no luck. I even replaced the headlight switch on the steering column with no luck. Has anyone had this issue or have any idea where to look? I am not great with electronics so this is baffling me right now. Thank you.

 

When any one unrelated circuit has an effect on another circuit, in your case a 12V constant circuit, [head lights] and a 12V switched circuit, [gauges and starter] it is almost always a grounding issue, recheck your grounds, DO NOT just eyeball them, redo them, disconnect/clean/reconnect, pay close attention to your main grounds, batt. to chassis and chassis to engine.

Do the same with your main power connections, batt. to starter, batt, to engine bay fuse box and the main fuses. 94

 

I took your advice and actually put in new grounds for the battery and engine and I think that was the problem! Even though I had already cleaned the grounds, the wiring must be old or something. The car has gone 3 days now with no issues leading me to believe it is resolved. I appreciate the advice.

 

94