I'm putting my dash back together and the label fell off this rather large brown lead with a connector on the end.
I can't find it in the AIM and/or the wiring diagram.

Any ideas?

there is a 12 BRN that goes to the ignition switch ?

A 14 BRN that goes to the HTR Switch.

hope that helps

That looks like an 18 gauge wire.
Also a brown that goes to the wind shield wiper solenoid I believe is the gold color one in the pic

....and says it goes to radio capacitor. See image.

-- it's right with the bundle for the ignition switch connector.

Does that seem to make sense? It looks like a "12" and it's "BRN" too... fairly hefty for wiring behind the dash.

Hi c,
How about here?
Regards,
Alan

I thought that in A/C cars, the additional A/C harness plugged into that connector.

I was thinking that was where it went, but I didn't want to screw up now. I'm fairly good about labeling so I'll relabel this guy.

My car did not come with a/c (I installed hot rod air about 10 years ago).

You'd think that a wiring diagram would include the capacitors being used, eh?

Now that I'm curious, why would a ~12 gauge lead be going to a capacitor?

Many thanks

If memory serves me, the A/C harness splits there for a lead to a capacitor, and the other 14 gauge wire to power the A/C unit. Gm probably just installed one wire in the main harness that could work in either situation. Does anyone have a picture of an unmodified connection?

...in the a/c section, and could not locate much. I find it interesting that this lead was run and just ends in a capacitor.

Hi c,
That capacitor is one of the four installed in the dash area on cars which had a radio as an option.
I see it in the AIM in the Radio Option sheets in the back.
For 71 it's UPC U69, sheet A3. Item#7.
Regards,
Alan

Alan nailed it again!
I have the same brown wire connected to a capacitor in the same location as well.
My car is a 1968 w/ U79 code radio and factory AC.
As stated this capacitor was used on factory installed radio cars for noise suppression.
The fan motor capacitor is in line with the fan motor under the hood.
This is in place, I believe regardless if you have AC or not.
All cars except maybe an L88 had a heater/defroster hence a fan motor.
This way you didn't hear the engine's whine as you accelerated through the radio speakers.
I drew a scratch paper diagram of the bulbs and all connectors when I removed my lower dash to replace the headlamp and ignition switchs about a year ago.
Surprisingly the capacitors still work.
Hope to have been of some help.
Marshal

SO the radio delete cars did NOT have that capacitor? Am I understanding that correctly?

Hi TAT,
There were no radio delete cars.
All radios were options.
A car with the ZR1 option and a few others were not available with the radio option.
Any car (68-72) that didn't have a radio as an option got the block-off plate in the center gauge bezel, none of the radio parts including the speakers, none of the 'radio' capacitors in the interior and engine compartment, no radio shielding on the engine and distributor, and no antenna or hole on the rear deck.
Regards,
Alan

"Radio Delete" sounds racy but it's really not accurate.

I see in AIM UPC-69/A-3 several capacitors for my 1968.

I gather this lead must be either to item 8 or item 12.
It looks like item 8 is for the brakes, so ---
the brown lead being discussed must be for item 12 at the ignition switch...especially since the old capacitor was mounted on the backside of tachometer.

The oddball part about that is that in this section of AIM it would appear that the lead comes from the ignition switch itself, whereas in reality it comes out of the harness bundle as shown in AIM UPC-12/B-6 (see above).

Oh well, my new radio doesn't seem to overly affected by lack of capacitors, so I'll just hook this guy up. Thanks for all the help.

Hi Marshal,
If it's easy enough for you to do so could you post a copy of the drawing you made?

That's what I was thinking-- I'm in the middle of replacing all of the wiring harness stuff- My 69 has not had a radio for years, (can't hear it anyway), so I'm not going to reinstall the capacitors. I'll just wrap stow all of the cap leads.

I'll look and see if I can find it and scan it.
Its a sloppy pen written set of circles showing back of tach and speedo bulb hook up by color code of wires.
Its in my flip notebook I think.
The brown wire would not be for the tach as they were mechanical for 1969.
The buzz can come from the alternator, distributor, wiper, fan motor, turn signals and the dreaded "POP" heard from applying the brakes.
There may be another I missed but these components generally needed a capacitor when radio equipped.
These are a mute point if you are using a modern radio.
The old transistorized radios were subject to interference.
A modern digital radio will not be effected by any of the other components most likely.
Marshal

It would something to look at.

As you can see in the image attached (AIM UPC-69/A-3 in post #14) above, there is a capacitor (#12) attached to the backside of the tach which goes to that imaginary lead coming from ignition switch....the capacitor mounted there is not for the tach, but apparently for the radio.

And, in the separate image (AIM UPC-12/B-6 in post #4) that lead in the ignition switch bundle is identified as going to the "radio capacitor" (which I gather is the one shown as mounted on the backside of the tach.

That is another reason your marked-up drawing might be really useful....to ascertain where things went.

Hi c,
Here are 2 of the sheets from the radio option pages in the 71 AIM.
I see the capacitor on the ignition switch you mention. I guess the capacitor's location moved when the ignition switch location moved in 69.
I don't know if they'll be of any use to you or not.
Regards,
Alan

The interior….4 capacitors, I don't know if this is any different from what you posted (except the switch location):


The engine compartment….2 capacitors:

The relocation of the ignition switch from the dash to the steering column kinda-sorta makes sense along with the AIM pages showing the relocated capacitors.
Fascinating..... and it adds up

It does help. Since the 68 AIM is so wishy-washy with that ignition switch wire; I figure this pretty much wraps up that the brown lead (along with your earlier picture) just goes to capacitor.