Painless wiring help 69-74 gm harness

[Dmaxed]

Painless wiring questions


1. I am trying to figure out what this tan wire is with the red female bullet connector. The wire is about 1 ft long and comes from the firewall connector. I can't see any markings on the wire. This is from the painless gm muscle car harness 69-74. I called painless and the tech said he couldn't believe the wire wasn't marked and said he didn't know what it was. Anybody know?




2. I am trying to plug in the backup light/reverse light switch from my 6 speed magnum trans. There are 2 wires in the painless harness that I'm supposed to route to the trans labelled backup light switch. The plug has 2 wires for the trans. Do I just connect the 2 wires for the backup switch to the harness wires or is 1 a ground wire?

Sorry for not having a pic at the moment. I have been having an issue with uploading them. If nobody knows the answers without the pic let me know.

thanks.

[ChevelleNV]

Try tracing the wire back to the fuse panel and see what circuit it is connected to, or you could also go through and mark off every wire you can identify in the instruction manual and see whats left over.

[sjaroslo]

Pretty sure tan wire is for parking brake switch.

[Dmaxed]

So I traced the wire through the firewall connector and fuse block. It splits to 2 wires. 1 looks like it goes to the the e-brake pedal connector and the other goes to the dash and instrument panel, I assume for the light. So what does the wire on the engine side of the firewall need to be connected to?

[sjaroslo]

Maybe I misunderstood your question but on my AAW harness, the one-foot-long tan wire comes off of the fuse block. I believe this represents the ground side of the parking brake light circuit. When you apply the parking brake, it allows the plunger on the switch to make contact, lighting the idiot light on the dash. When you release the brake, the switch is opened, breaking the circuit. But if your wire is on the firewall side, then I'm less certain. Are you sure it didn't accidentally poke through by mistake? Of course, I'm basing my advice on a harness for a 67 Camaro made by another company, so I could be off in left field, sorry.

[sjaroslo]

2. I am trying to plug in the backup light/reverse light switch from my 6 speed magnum trans. There are 2 wires in the painless harness that I'm supposed to route to the trans labelled backup light switch. The plug has 2 wires for the trans. Do I just connect the 2 wires for the backup switch to the harness wires or is 1 a ground wire?

Not sure if this answers your second question, it is from the American Powertrain installation instructions for the 6-speed:

"Splice the new reverse light wiring harness into your existing harness by removing the modular plug. The reverse switch is non-polar."

[Dmaxed]

Thanks for trying to help Steve. I will get it all figured out at some point.
All I can think of is that it would be connected to transmission running down the firewall and under the floor. I don’t think I need it because I rerouted my third brake light wire (no third brake light on the Nova) under the dash and plan on running it along the trans tunnel and out the shifter hole to the trans for the reverse lockout switch. The brake light circuit gets grounded out at the rear of the car. According to the original wiring diagram the brake wires are not connected until you press the brake pedal activating the switch, which flows power to the tail light/brake light. The light is then connected over to the rear side marker light (integrated brake lights, 2 filament bulbs in the brake light) and then a ground wire is connected to the tail lamp housing bolt. As far as the reverse light switch I think I just connect the 2 back up light wires to it with no ground. I think the circuit is already grounded at the reverse light housing because it is metal and so is the light socket.

[astroracer]

The tan wire on ALL GM applications goes to the Brake Pressure Switch in the Proportioning valve.

[Jetfixr320]

I've only installed one Universal painless kit harness. But, there installation instructions had all of the wires listed if IIRC.

If all else fails, call their tech support. They were pretty helpful with any issues I had.

[sjaroslo]

"The tan wire on ALL GM applications goes to the Brake Pressure Switch in the Proportioning valve."

I think that you have your winner right there!

[Dmaxed]

Jetfix. I tried their tech support and the guy I talked to had no idea. It seems as though Mark had the correct answer. I appreciate it very much. I think I can just wrap mine up and stow it though be because I'm not seeing anything on my Wilwood prop valve to connect it to.

[lbluecamaro69]

Yeah it should go on the top of your prop valve