What the heck is this switch under my dash? - Third Generation F-Body Message Boards

itzkramer · 09-16-2009, 06:54 PM

Hello, all. I've owned an '78 Z28, and i currently own an '80 Z28. I just got my first 3rd gen today, an '85. Well the 3rd gen sure does have a lot more going on under the hood and dash, so im all sorts of confused. So if you will, please bear with me, and answer some very simple questions for me as i work on my new car.

I found these wires all tucked up under the dash on the far drivers side(see below). It includes a very small 3-way switch. The car does not have a radio currently. Never seen anything like it. Any ideas?

Also, where the hell is the main battery fuse, and the fuse box on this car? Simple question, i know. But after looking for 45 min online, not a single picture of the damn thing.

The previous owner says it needs a fuel pump. Ive verified this by starting the car, and kept it running for a few seconds on starting fluid. Otherwise, it just cranks. Also, no sound from the fuel pump priming. I checked the relay, and bridging it does not cause the pump to prime. Ive decided to do the fuel pump access hatch mod(no comments on that, just leave it be

). Not really a question, but i suppose ill have some along the way.

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Chevy8588 · 09-16-2009, 08:04 PM

looks to be an aftermarket alarm system was there at one point in time

Toehead · 09-16-2009, 08:31 PM

the fuse box should be on the drivers side, about where those wires are coming out!

+1 on the aftermarket alarm.

bm87ta · 09-16-2009, 10:05 PM

agreed, valet switch for the alarm system

itzkramer · 09-16-2009, 10:10 PM

thanks for the info. do you all agree on the fuel pump being the problem, and not a relay switch problem or somthing else?

i just want to be sure before i drop the cash on a new pump.

TPl383 · 09-16-2009, 10:17 PM

if y9ou jumped the relay and no power to the pumps Ya id say its dead.
Try taking a multimeter and testing the wires at the plug under the car by the rear end where it plugs in.

You can jump 12v to the pump from there also.

Hopefully those wires/alarm didnt interupt the fuel pump power as a anti start setup. Most alarms dont unless they are high end ones.

Chevy8588 · 09-16-2009, 11:23 PM

pull that wiring out and reconnect everything stock,it probably had a fuel pump interrupt on there, shouldn't be too difficult to match everything back up. i do NOT think the fuel pump is the issue here - ex GM tech

camaronewbie · 09-16-2009, 11:25 PM

Did you try flipping the unknown switch and seeing if the fuel pump runs? Maybe both problems are one.

Check the fuse tucked in the fender well behind the battery before simply replacing the pump - this fuse has to do with pump operation - it's a single fuse in a weatherpack with an orange and red wire running to it.

itzkramer · 09-17-2009, 07:58 PM

got the fuel pump working. it was a main battery fuse/fuel pump combo. replaced both, and it works fine. i put on some temporary rubber fuel hose to test it, but all the lines will be getting pressure fittings soon.

the switch isnt hooked to anything, so thats good.

but now i found a coolant leak. dammit.

Mike M · 10-08-2009, 07:54 PM

Yep definitely an aftermarket thing. Most likely part of an alarm system.