Odd wiring find under the dash...
Thread Starter
Safety Car
Joined: Apr 2002
Posts: 4,653
Likes: 6
From: North Royalton, OH
St. Jude Donor '06-'07
Odd wiring find under the dash...
As I was working on my '71 throttle cable today, I see a resistor dangling in front of my face, attached to the brake switch. Since it's attached with a couple blue splice clips, I'm thinking Bubba was here long before me, and I took the thing off and taped over the small holes in the wires. Did he have some radio interference in his Pioneer Supertuner back in '76? Who knows? Anyway, problem solved.
Forward to a bit later this afternoon, I'm digging through an old spare wiring harness, snipping needed clips and wires, when dang if I don't see the EXACT SAME FIX on this particular harness (from a '74, and from far, far away from where I live, so Bubba would have to have a twin). So here is the "fix" I saw hanging in my '71:
And here is the resistor (?) I took off my car a few hours earlier - again, in exactly the same place with exactly the same clips.
Did I just undo some factory fix of some kind? Here I thought I was doing myself a favor... Anyone (everyone?) else have this thing?
Forward to a bit later this afternoon, I'm digging through an old spare wiring harness, snipping needed clips and wires, when dang if I don't see the EXACT SAME FIX on this particular harness (from a '74, and from far, far away from where I live, so Bubba would have to have a twin). So here is the "fix" I saw hanging in my '71:
And here is the resistor (?) I took off my car a few hours earlier - again, in exactly the same place with exactly the same clips.
Did I just undo some factory fix of some kind? Here I thought I was doing myself a favor... Anyone (everyone?) else have this thing?
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Factory doesnt use the cheesy sqeeze taps, at least I have never seen it.
I agree it was to cure the "pop" which was very common with some music radios of the era...it would also "pop" in some CB radios also popular in those days....some people who be far more bothered by the pop than others....
I agree it was to cure the "pop" which was very common with some music radios of the era...it would also "pop" in some CB radios also popular in those days....some people who be far more bothered by the pop than others....
Melting Slicks
Joined: Sep 2005
Posts: 2,720
Likes: 904
From: Warminster PA
A bit of clarification, that is a capacitor, not a resistor.
It was probably installed to supress the radio noise generated when the brake pedal is depressed as indicated in previous posts. The brake switch would arc when the switch contacts were opened and closed. The capacitor would "absorb" the arc effectively eliminating the pop heard in the radio.
Tom
It was probably installed to supress the radio noise generated when the brake pedal is depressed as indicated in previous posts. The brake switch would arc when the switch contacts were opened and closed. The capacitor would "absorb" the arc effectively eliminating the pop heard in the radio.
Tom
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Thread Starter
Safety Car
Joined: Apr 2002
Posts: 4,653
Likes: 6
From: North Royalton, OH
St. Jude Donor '06-'07
Thanks, Tom - I thought I had it wrong... Maybe this was one of those dealer repairs from a service bulletin if the customer complained of this particular noise. Sounds like I need to put it back on 
And I'm glad to hear others have the same thing - still cheesy with the snap clips!
And I'm glad to hear others have the same thing - still cheesy with the snap clips!
Le Mans Master
Joined: Jan 2006
Posts: 8,246
Likes: 114
From: Watkins Glen NY
My 69 has those same quick clips and capacitor under the column, and I haven't found a single cut or bubba'd wire anywhere inside the car. I would think they are original, except I don't know if that type of solderless connector even existed back then.
There are at least three capacitors on my car that I can think of right now...brake, blower motor, and one behind the cluster, wired into the clock IIRC.
There are at least three capacitors on my car that I can think of right now...brake, blower motor, and one behind the cluster, wired into the clock IIRC.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
I think I read somewhere this was a Chevrolet field campaign in the early 70s to help with radio noise, but I can't find any proof. All the 68-72 harness I have seen have that capacitor.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
That is a capacitor which is used to suppress 'clicks/pops' in the radio sound when you activate the brake pedal. And, yes, the cheezy blue clips were installed by the factory and/or the dealer. Apparently, it was a design change from the original wiring diagram and done that way for a period of time. If you have upgraded to a modern radio system, you don't need that noise filter...unless you wanted to keep it 'stock'.
P.S. You will find other similar 'noise filters' on the alternator, the ignition coil, the blower motor, etc. throughout the electrical system. Who knows if these old capacitors still function?
P.S. You will find other similar 'noise filters' on the alternator, the ignition coil, the blower motor, etc. throughout the electrical system. Who knows if these old capacitors still function?
Drifting
Joined: Oct 2007
Posts: 1,317
Likes: 22
From: Marina CA
Those were installed by the dealers when a customer complained about the popping in the radio on the AM band. We also installed them on the turn signal flashers.
The Scotchlock wire taps were used because they installed quickly. Not the best way to splice into a wire but most shops were "flat rate" so the pressure to meet or beat it was always there.
The Scotchlock wire taps were used because they installed quickly. Not the best way to splice into a wire but most shops were "flat rate" so the pressure to meet or beat it was always there.
Melting Slicks
Joined: Sep 2005
Posts: 2,720
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From: Warminster PA
I hope to take a look under the dash of my 71 tonight and see if there is one installed.
Tom
Heel & Toe
Joined: Nov 2007
Posts: 19
Likes: 0
From: Holmes Pa
I have a 69 and the capacitor and clips are there. It is definitely factory at least on the 69 and I suspect yours also. No bubba job, it shows this exact configuration clips and all in the 69 assembly manual under the radio option section. it is just supposed to be taped to the brake light switch connection.
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Factory capacitor for radio noise supression. They didn't work effectively even when they were new.
Thread Starter
Safety Car
Joined: Apr 2002
Posts: 4,653
Likes: 6
From: North Royalton, OH
St. Jude Donor '06-'07
Well, I for one am glad to hear all this good news 
I reinstalled mine in the same location last night, if nothing but for originality... I can't ever remember hearing pops on the radio when I hit the brakes (with side pipes, what CAN you hear, really?) so maybe it was actually working. I'm almost sorry I popped off the original cheesy clips! They fell apart pretty easily, and the metal connectors were pretty corroded, so I'm guessing I didn't hurt anything... 
I reinstalled mine in the same location last night, if nothing but for originality... I can't ever remember hearing pops on the radio when I hit the brakes (with side pipes, what CAN you hear, really?) so maybe it was actually working. I'm almost sorry I popped off the original cheesy clips! They fell apart pretty easily, and the metal connectors were pretty corroded, so I'm guessing I didn't hurt anything...