I have a 87 camaro and have some odd problems. With the key turned to the on position (car not started) If i turn on the lights my Fuel pump primes.

Also with the key turned to on position or car running the heater/Ac Fan control will not work on the 4th fan speed. Speed 1,2,3 works fine but soon as you turn it the 4 it shuts off. Any ideas????

 

Fuel pump should prime almost every time the key is turned to on. But are you saying if the key is turned to ON and left thee for 5 minutes, and then you turn the lights on, the pump will prime again?

The blower - maybe bad relay - there's a relay attached to the heater box under the hood - the relay runs the HIGH speed of the fan motor - check that.

 

Yeah, The Key is in the On position, fuel pump primes (normal) then if i pull the head light switch the fuel pump primes. This is with the car not running.

I will check the relay thanks!!

 

Weird on the fuel pump/lights issue - never heard of such.

Is there any weird wire connections at the fuse box where someone tried to get power for an accessory? There really truly is no physical connection between any lighting circuits and the fuel pump priming (which is controlled by the ECM).

Sure it's fuel pump repriming and not electric hatch motor or something else? I could see where a lighting wire (hatch light) could get crossed with a electric hatch motor connection (since those wires are right there together).

 

There are a few things wired in ACC Alarm and a few switches. One thing is wired to the light switch, my A piller gauges. Far as what i am hearing it is the fuel pump because you can watch the fuel pressure gauge on the fuel rail..

Ill try disconnecting the things in Accessory.

 

I just got done disconnecting every thing in Accessory and it still primes.