Hello everyone! First I would like to say that I've been having this problem for the last three days and I've been searching but couldn't find anything similar to what happening here

My 1989 S5 rx7 started blowing the under hood 30A headlights fuse.

They work fine with the car turned off or at idle,, as soon as I tap the accelerator it blows the fuse


I've checked wiring from headlights and followed as far back as I could, didn't find any problems. Replaced the bulbs with quality units, no change

Alternator was putting out 14.69 Volts at 2k rpms. I suspected a bad regulator so I purchased a reman alternator from oreilly's, installed and no change! Still 14.69V and still blows the fuse.

I'm out of ideas! Maybe anyone can chime in.

Every thing else on the car works perfectly fine and nothing has been cut or hacked.

The anti theft system has never worked but I don't think it's related.

Any help is much appreciated

 

What happens to the fuse when you are driving w/the lights off? Does it still blow?

 

No sir, as long as I don't actually move the switch to the on position it won't blow, also parking lights work fine, it's just the headlights

 

That's a head scratcher. To narrow things down possibly you might want to unplug the headlight switch. Then go to the headlight relay and jumper the White/Blue wire to a ground and the lights should turn on (won't pop up but just turn on). Do this w/the car running and then press down on the accelerator to see if the fuse continues to blow. The head fuse runs to both the headlight relay and the headlight switch.

 

Hmmm that's a good idea , would it be easier to try a spare headlight switch?

 

You don't know what the cause at this point is so you might be jumping the gun by replacing parts before you diagnosed the problem.

 

if you've got a switch sitting around and a bucket of fuses I dont see the harm in trying a different switch.