Here's a question for the stereo guys: This connector is dovetailed to the line that provides power to the radio (a stock Delco head unit - cassette, no graphic equalizer). I didn't notice it before, but when I was holding the head unit in one hand and pulling out the console with the other hand (not much slack in the wiring...thanks, GM!), the head unit got away from me, and that's when I noticed this little bugger. Can anyone tell me what it is and where it goes?

 

do you have a larger image, I can't really see it.

 

cdoyle, here's a bigger picture. Is it by chance the connection to whatever early OBD equipment the dealers used? I don't want to put the whole thing back together only to have to take it apart again!

 

hmm, that is just not looking familiar. I don't think it would be any type of OBD, since they have a dedicated plug under the dash for that.

What year/model is your car?

You only have the one plug on the back of the deck right?

 

cdoyle, it's an '89 Trans Am with a 305. As far as I can tell, that's the only one, and I'm having trouble finding any place on the head unit to accommodate it. That's what's so confusing.

 

That wire that I said provides power to the head unit is actually an antenna lead. But strangely enough, I turned on the radio and the HVAC controls to see if everything would work, and everything (seems) to work just fine. Now I'm even more confused.

 

Do you have steering wheel controls? The option is normally on GTA models. Being an 89, you have a 20 pin connector on the back of the radio, of which a six pin section is unused. Steering wheel controls (if that's what it is) would plug in to that unused section, but I forget offhand which pin. IIRC, it's just next to the four pin connector for speakers on that row of the socket.

 

Al, I don't have steering wheel controls. I tried looking everywhere for a logical place to plug it in, but couldn't find one. Is it possible that all TA's were prewired for steering wheel controls and since I don't have any, that plug just stayed there unused?

 

think your best bet would be to try and pull up a wiring diagram for this site... i'm sure its out there and then look for the color coded wires.. i got no clue when it comes to firebirds..

 

I've been doing that all day...the free ones are crappy and tell you nothing. Then there are ones for $5 dollars that are also probably crappy and tell you nothing.

A theory that more than one person today had is that it might be a lead for optional equipment that wasn't installed, like an amplifier or steering wheel controls. I like that theory.

 

It is the steering wheel control connector. No, not all Trans Ams were wired for it, but all GTA's from 87-89 were, with the rare execption of 89 with CD player option.

 

eseibel, I don't have a GTA or steering wheel controls. Is it at all possible that the wiring for certain models (like the Trans Am, Formula & GTA, not the Firebird) were wired that way because of the different sound systems available for those models?

 

Regular TA was also available with steering wheel controls. Not sure if you know the history on your car, but is it possible that a PO removed the wheel? The leather on those wore out fairly quickly.

As far as the wiring, yes, it's common practice to pre wire for options not installed. I doubt the General did that in this case, however, since the turn signal switch is specific to cars with radio control steering wheels because it has an optical sensor in it.

 

AFAIK, my car didn't come with steering wheel controls (or get the wheel replaced). After checking out my SPID against RPO Codes.com, these are the "U" codes that I found:

UB3 : CLUSTER, INST, OIL, COOL TEMP, VOLTS, TRIP ODOM, TACH
UF6 : LAMP, INTR, CONSOLE, COURTESY
UM6 : RADIO, AM/FM STEREO, SEEK/SCAN, AUTO REV CASS

UQ1 : RADIO PROVISIONS, FOR STEREO (Could this be the explanation for the extra lead?)

UT1 : TONE GENERATOR, WARNING
U25 : LAMP, INTR, RR COMPT, COURTESY
U29 : LAMP, INTR I/P, COURTESY
U62 : SPEAKER SYSTEM, DUAL COAXIAL
U75 : ANTENNA, POWER, RADIO

(I don't have this option, but it's the only one I can find that addresses steering wheel controls) UT4 : RADIO, AM/FM-ST CASS, AUTO NR, TOUCH CONTROL, STEERING WHL

The car's only had one PO who put about 2,500 miles a year on the car. He babied it.

Since no steering wheel control code comes up on the SPID, do you have any other thoughts?

 

I checked the RPO's on my son's GTA that does have the steering wheel controls:

NK4 is the steering wheel
UT4 is the specific radio that is controlled by the wheel
UQ1 is the radio provision, that might explain your extra plug

If you ever have the steering wheel off, take a picture of the turn signal switch to confirm.

 

I only have the UQ1 code on my SPID. As long as that connector's not supposed to be plugged into anything, I'm happy. I'll try to remember to get a picture of the turn signal switch tomorrow morning.

 

eseibel, here's a picture of my turn signal lever.

 

I meant the turn signal switch. You need to have the steering wheel and lockplate off to see it.

 

Oh...I doubt I'll ever have the steering wheel off unless it's absolutely necessary!