what?? electric fuel pump comes on when I turn the lights on??

[jerman]

73 240 auto... the problem is with the car off I can turn the light switch on and the fuel pump turns on. The other issue is all lights not switched (gauges, side marker, fog, tail etc) come on without turning them on. The headlights work properly with the switch. So basically I have to run with all acc lights on when car is running. Has anyone ever heard of something like this? I've searched for shorts/grounds etc etc can't find any obvious wiring miscues. Just hoping that someone has experienced this issue and knows the fix. Thanks

[Stanley]

Have you tried prayer? If that doesn't work I would definately try cursing, or hitting things.

BTW, my 63 chev has only 6 wires, 12 if you count the plug wires.

[Mikes Z car]

Did your car always do those things or are they all new behavior?

My personal favorite is to go berserk.

Edited November 5, 2012 by Mikes Z car

[SteveJ]

It depends. Was the fuel pump added by some jackwagon who didn't know his head from a hole in the ground? Was the fuel pump installed in accordance with factory directions? What wiring modifications have been made to the car?

The factory's implementation of the electrical fuel pump involved the addition of two relays. One relay coil energized with the starter, and the other tapped in between the alternator and voltage regulator to power the coil. If either coil was energized, the circuit was completed for the fuel pump to get power. I can't think of any way the factory method could cross-connect with the headlight circuit. It smells like an idiot with wire strippers to me.

[jerman]

Did your car always do those things or are they all new behavior?

My personal favorite is to go berserk.

Yeah, the car wasnt running when I bought it. I had to put new carbs on it to get running. It's been that way every since. Already done the "berserk" thing many times.

[jerman]

It depends. Was the fuel pump added by some jackwagon who didn't know his head from a hole in the ground? Was the fuel pump installed in accordance with factory directions? What wiring modifications have been made to the car?

The factory's implementation of the electrical fuel pump involved the addition of two relays. One relay coil energized with the starter, and the other tapped in between the alternator and voltage regulator to power the coil. If either coil was energized, the circuit was completed for the fuel pump to get power. I can't think of any way the factory method could cross-connect with the headlight circuit. It smells like an idiot with wire strippers to me.

you may be on to something... the car doesn't have a voltage regulator, the alternator has been upgraded to internal regulator and has had the E12-80 electronic ign module upgrade. I bet the "idiot" that did that probably screwed up the circuit in the process. I have a harness (24034-N330) that does have a relay (25230-89915) on it but I can't find any wiring diagram that shows this connection. Do you think the same relay was used on the later 260?

Edited November 6, 2012 by jerman

[SteveJ]

I haven't run across a wiring diagram for the relay circuit. I pulled out the connection between the alternator and voltage regulator in my 73 a few years after I put in an internally regulated alternator. I didn't even realize what it was for at the time, but I did notice that the battery stopped running down.

I would imagine that the logic would be the same as for the 260Z. However I don't know if they used the same kit.

[jerman]

After prayer, banging my head and nearly going "berserk" I finally just started pulling wires until the problem was solved. So it all stopped when I pulled a small 3 prong connector. The car has never had a stereo in it since I've had it nor any antenna so I think it is the plug to power the stereo and the plug to power the electric antenna were connected together. Well the best I can tell from the FSM. I do know that the problem is solved... HALLELUJAH!