I pulled the old carpet out of my 1971 Cutlass Supreme and found two mystery wires lying under the passenger seat:

(1) One is a yellow wire that is very long (12+ feet) and goes up the firewall on the passenger side near the heater box.

(2) The other is a blue wire that goes up the firewall on the passenger side and looks to lead to the center of the dash.

Any ideas what these are for?

Scott

P.S. I am unable to attach the pix I took and would appreciate some insight as to how to do this.

 

Do you have an electric trunk switch?

 

Blue would be for rear radio speaker.
Yellow ~might~ be for rear defroster - do you have that option?
If not, it could be for the seat belt warning circuit, but I was thinking that system came out for the 1972 models.

 

In big cars (65-66) purple is used for rear defroster.

 

Blue sounds like its for the rear speaker and yellow possibly for the electric trunk release... but either could be for anything at this point depending on what was added, changed etc after all these years.

 

Rob, I think your right that the seat belt warning wiring didn't start until 1972. I've pulled those parts and think the yellow wire had a black stripe on it too. John

 

Trace them all the way to where they end.

A lot of OEM wires ran together in a flat plastic channel under the driver's feet, but not all of them - I believe I recall the stereo speaker wires ran under the passenger carpet without a channel. I'm pretty sure the trunk release wire was black.
I believe that a single-rear-speaker car would have the speaker wires running as a pair (moulded together, like zip-cord), and not as two individual wires.

Could one or both be for a rear power antenna?

- Eric

 

The blue wire is almost certainly the rear speaker wire.The yellow wire is anybodys' guess.

 

Thanks for the information, guys.

No, there is no remote trunk option on my car.

The car is a convertible with an after-market stereo + 2 rear speakers in the convertible well behind the rear seat. I found the speaker wires to those speakers so this makes sense.

Since the car is a convertible, I don't have this option.

These wires were loose on the passenger side.

My car has the antenna in the front windshield.

Here are the pictures:

DSC02111.jpg

DSC02112.jpg

 

The blue wire is your rear speaker wire - it comes from under the firewall insulation, follows the factory channel in the floor, and has a factory attaching clip still on it, and is the right color and texture. The other end should be hanging somewhere behind the radio.

The yellow one was added later - it's too kinky (strands too thick) to be original, and comes from between the heater box an the firewall insulation, which can't be original. Not sure what it's for, but maybe someone had a rear blower fan installed that went on with the heater blower. If you find the other end, you'll know (and maybe prove me wrong...).

- Eric

 

I dug a little deeper last night and found that the yellow-ish wire in these photos is actually two wires soldered together. The yellow one was at the end of the line was not attached to anything, while the white one looked like some home cookin'.

It was a single/solid thread wire that started at the positive battery post, went through the firewall, under the dash to the central speaker area, out the bottom of the heater/AC (as shown in the photo).

I couldn't pull it out from the central dash area or the heater box so I just clipped the wires as close as I could.