HELP 1982 C100 Pinout

Texas82GP

Just-a-worm
Supporting Member
Apr 3, 2015
7,043
113
Spring, Texas
My Grand Prix was originally a diesel car with full gauges. When the previous owner swapped in a small block Chevy, he just made the diesel engine harness work, and taped up all the wires he didn't need. I initially just bobbed those wires and sealed them up. Later when I removed the dash, I had to dig past the diesel specific sound deadening to get to the bolt that retains the front light and engine harnesses to the C100 bulkhead connector. Now it's really a mess and I've decided to replace both the engine harness and the front light harness to clean this up.

Here's what the front light and engine harnesses look like on a diesel car......

20171203_154811 - Copy.jpg


I bought a reproduction engine harness for a 1982 Monte Carlo/Malibu/El Camino with a V-8 and gauges. I bought a front light harness for the same. My car is an 82 Grand Prix.

Last night, I located the pinout for the C100 connector (bulkhead connector) in my 82 Pontiac Grand Prix/Bonneville shop manual....

01-13-21_01.jpg


According to what I'm seeing in my shop manual, the pinout doesn't change relative to options (engine, gauges, accessories) and is standardized across the 82 Grand Prix/Bonneville.

Here's my question: Is the C100 pinout the same for the 82 Chevrolet Monte Carlo/Malibu/El Camino? If anyone has an 82 Chevrolet Shop Manual, would you please find this diagram in the book and post a picture of it?

My guess is this pinout is standard across all the G-Bodys until the C100 connector changed a few years later but that is just an assumption. What I ultimately need to know is, do I need to repin my new engine and front light harnesses to get them to marry up correctly with my Pontiac bulkhead connector?

Thanks Guys!
 

DRIVEN

Geezer
Apr 25, 2009
7,125
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*CENSORED*
I don't know if it's pinned the same or not, but I suspect your assumption is correct. GM was as lazy (frugal) as can be. No need to make specific pinouts for each marque. Then they'd need different engine harnesses for a 3.8 in a Chevy, 3.8 in a Pontiac, 3.8 in a...
You get the idea.

On the body harness, I suspect the pinouts are the same there too. Not sure about wire lengths though.
 
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Texas82GP

Just-a-worm
Supporting Member
Thread starter
Apr 3, 2015
7,043
113
Spring, Texas
I don't know if it's pinned the same or not, but I suspect your assumption is correct. GM was as lazy (frugal) as can be. No need to make specific pinouts for each marque. Then they'd need different engine harnesses for a 3.8 in a Chevy, 3.8 in a Pontiac, 3.8 in a...
You get the idea.

On the body harness, I suspect the pinouts are the same there too. Not sure about wire lengths though.
Agreed. And I recently read about a member using a square body engine harness on one of these cars, which further supports the theory. I just want to know for sure before I get too far along. On a whim I looked at the price of 82 Chevrolet Impala/Malibu/Monte Carlo/El Camino factory shop manuals online and they were so inexpensive I went ahead and bought one, in case someone with the same book never comes along to answer my question. I'll post up when I have the answer if nobody else has already, by then.
 
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Texas82GP

Just-a-worm
Supporting Member
Thread starter
Apr 3, 2015
7,043
113
Spring, Texas
Circling back to close this out more or less. I bought an 82 Chevrolet B/G shop manual....
20210119_191409_copy_2016x3584.jpg


I had hoped to find a diagram like the following, which is from my 82 Pontiac G platform shop manual....

20210113_190536_copy_1134x2016.jpg


It wasn't quite that easy. There wasn't a similar diagram in the Chevrolet manual. However, there is this in it....

20210119_191523_copy_2016x3584.jpg


Zooming in, here are the engine and front light harness plugs....

20210119_191614_copy_2016x3584.jpg


And the corresponding charts....

20210119_191923_copy_2016x1134.jpg


20210119_191938_copy_2016x1134.jpg


20210119_192023_copy_2016x1134.jpg


20210119_192051_copy_2016x1134.jpg


I cross checked all pins and they match, with the exception of the pin labeled 931 on the engine harness plug in the Chevrolet manual. There is no 931 on the charts. It appears to be a typographical error. It shows to be light blue/choke heater on the corresponding pin on the Grand Prix C100 connector.

Now I just need to check that pin on the reproduction harness. It looks like the pinout on the C100 connector was standardized at least between the Pontiacs and Chevrolets, and I'm guessing the rest of the marques as well.

I'd be interested to hear what the guys who have swapped Pontiac dashes in their Chevrolets have to say about it.
 
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