Thoughts on these wires?

[Z71Tahoe2004]

2004 Chevy Tahoe Z71 w/ ~218,000 miles.

I'm replacing my aftermarket receiver with an upgrade and spent some time today pulling out the previously installed aftermarket harnesses. It was a bit of a mess. Got everything out, leaving only the original GM radio and OnStar harnesses. But, I found this duo of wires connected to the old aftermarket harness with a couple of spade connectors. Three wires (green, orange, and purple) coming up from somewhere in the dash. The purple was taped off and not connected to anything, the orange one was connected to the aftermarket radio harness (Pioneer AppRadio 4), and the green was connected to a PAC steering wheel control box. Pictures below.

Wondering if anyone has any ideas on why the installer would have need to do this and if it's going to complicate things when I go to install the new stuff - as in, will I need to get these wires hooked up again if a previous installer has done any permanent alterations to the factory wiring from the main harness.

Appreciate any help anyone might provide!

 

[2010gmcyukon]

I'm not sure about the orange wire, but I believe the Purple is usually a power hookup for a backup cam, and the green goes to the parking brake. Can you see where they go?

 

[Doubeleive]

Green could also be the speed sensor which is usually taped from the green wire behind the instrument cluster, but really your just going to have to follow them back to there source since they are single wires should be very easy.

 

[Bear77]

IIRC, for pioneer radios, the purple wire is most likely the reverse trigger wire. The orange for the dimmer circuit and the green for parking brake. Should be able to pull out the headlight switch to double check that one. The other two may be behind the drivers kick panel or in the convenience center?


Sent from my iPhone using Tapatalk

 

[Wylie_Tahoe]

orange on a head unit is illumination. What was that orange pictured above, connected to?

 

[Z71Tahoe2004]

orange on a head unit is illumination. What was that orange pictured above, connected to?

Orange one was connected to the aftermarket radio power plug (with its other wires). I pulled the install manual for the AppRadio and it looks like orange is for illum - so yes - this makes sense.

 

[Z71Tahoe2004]

Green could also be the speed sensor which is usually taped from the green wire behind the instrument cluster, but really your just going to have to follow them back to there source since they are single wires should be very easy.

Thanks! The green one looked like it was running to the PAC steering wheel controls, so I'll go ahead and trace it back to the source.

 

[Z71Tahoe2004]

IIRC, for pioneer radios, the purple wire is most likely the reverse trigger wire. The orange for the dimmer circuit and the green for parking brake. Should be able to pull out the headlight switch to double check that one. The other two may be behind the drivers kick panel or in the convenience center?


Sent from my iPhone using Tapatalk

Yes - purple on Pioneers looks like it's for a back-up camera, but the purple one in question was coming from inside the dash and was not connected to anything on the radio. The installer just tied it off and taped it to the bundle with the orange and green. Also - the 04 didn't come with a back-up cam as OEM on any model. Guess I'll need to follow it down its abbit hole. Thanks for the reply!

 

[Z71Tahoe2004]

So if orange is illum and green is the speed sensor, I wonder if the fact that these two may have, for some reason, been spliced in from elsewhere in the vehicle will make the install of the new radio more complicated. The new radio harness (Kenwood) and the PAC controller all have wires that should account for speed sensor and illum without having to rely on bringing them in from elsewhere in the dash, as the previous installer appeared to have done. May have to hook it up and see what doesn't work...

 

[Tonyrodz]

Yes - purple on Pioneers looks like it's for a back-up camera, but the purple one in question was coming from inside the dash and was not connected to anything on the radio. The installer just tied it off and taped it to the bundle with the orange and green. Also - the 04 didn't come with a back-up cam as OEM on any model. Guess I'll need to follow it down its abbit hole. Thanks for the reply!

The purple is for an after market camera. And usually the green wire is hooked into the reverse lights to trigger the camera on.

 

[Bear77]

It also could be that the purple wire was left there in case you decided later on to add a back up cam


Sent from my iPhone using Tapatalk

 

[Z71Tahoe2004]

Thanks for the comments thus far on this.

Here's an update after I removed more of the trim and traced the wires back to their termination points.

Orange wire ran back to the headlight switch on the dash, where it was spliced into a greyish-brown and white striped wire. Can't find anything in the Haynes manual electrical diagrams that says what that grey-brown/white wire does, but assuming that's what was being used to power the auto-dim feature on the radio.

Purple wire ran back to just outside the kick panel fuse panel on the driver's side, where it was spliced into thicker gauge brown wire that runs from the fuse panel up into the steering column. Haven't gone after that one in any wire diagrams, so not sure what it does. The purple wire wasn't connected to anything on the radio end, so not sure why the installer would have done that).

The green wire was spliced into a similarly colored green wire near what I think is the BCM and a pretty large harness under the steering column. The original green wire was cut at the harness (where it originally ran up into the steering column) and left uncapped and uninsulated. The new green one the installer put in was connected to the green wire that continued up into the steering column. Comments in this thread have said the green wire might have been a vehicle speed sensor, but since it runs up to the steering column, not sure that's what it was.

Additional pictures are below.

I'm going to repair the wires that were cut or spliced so that they are in the original factory configurations. My only guess as to why the previous installer would have done that is because they were either avoiding the need to spend more time wiring up a PAC adaptor or trying to find ways to shortcut with previously installed equipment. Weird though, because doing it the right way would have meant they could have made more money off of me. Hmm....

Once the repairs are made, the new receiver is going in along with a PAC RP5-GM11 - which should do all the things the radio needs for full functionality without having to splice anything outside of what the harness calls for.

If anyone recognizes any issues or has any thoughts, weigh in. Appreciate the insight and the help!

 

[ScottyBoy]

The brown wire in the steering column/ignition switch harness is an accessory wire. The greyish or ivory colored wire with the brown stripe is indeed the illumination wire at the headlight switch. Could have also grabbed that wire that the AC control panel just below the radio, lol. As far as the green wire, I'm not 100% sure but I suspect that it's the data wire for the steering wheel controls.

 

[iamdub]

Scott touched on this: Green is usually a data circuit, so I'd look at it as that rather than a parking brake, VSS or SWC circuit exclusively.

There could have been multiple setups prior to you that may have used different styles of SWC interfaces.

You're on the right track reverting everything back to stock to work with a clean slate and modifying only what's needed for your new equipment. With all the interfaces available now, you shouldn't have to hardwire for the dimmer circuits. You can even get an interface that has the SWC built into it.