Devin85

So, I have a 1985 Pontiac Firebird and I am at the beginning of doing an entire rewire of the engine side of C100 and I've noticed something about C100 for the Firebird vs most of the diagrams online (which are for the Camaro).

There are two popular sites for C100, AustinThirdGen.org and Berlinetta.info

I can't find a C100 specifically for a 1985 Firebird, there are only diagrams for "F" Car (written on the side or top of the pages). Does that mean the Firebird and Camaro for 1985 have the same wiring?
See here:
https://austinthirdgen.org/storage/C..._1985_C100.gif
https://berlinetta.info/media/shopma...Berlinetta.jpg

For all the Firebird specific C100 diagrams I've seen for 86-92, the connector is opposite of the Camaro for the same years.
See here:
https://berlinetta.info/media/shopma...00Camaro87.jpg
https://berlinetta.info/media/shopma...Firebird87.jpg

So, my main question is: Would a 1985 Firebird have the same orientation of C100 as a 1985 Camaro?
The C100 on my car matches the "F" Car diagram visually, though I haven't dove into the wiring to start tracing wires yet. I wanted to know if anyone knows that by following the 1985 "F" Car pinout, I'm looking at everything correctly.
It looks like my C100 matches the Berlinetta Camaro C100 (VSS wires going in).

Another thing that confuses me is my fuse block doesn't match the 1985 "F" Car fuse block, but it matches the 1987 Firebird fuse block.
https://berlinetta.info/media/shopma...seCamaro85.jpg
https://berlinetta.info/media/shopma...Firebird87.jpg

If anyone can shed some light on this it would be greatly appreciated.

Also, does anyone know what shop manuals were used for those electrical diagrams on Berlinetta.info? I purchased an old 1985 Pontiac Firebird GM Shop Manual, and it looks nothing like those pages.

ratfink6923

iTrader: (2)

"F" car means the body line. That covers both models.

Devin85

I figured it was referring to F Body, but just wanted to make sure I wasn’t missing something since 1986 and forward they were specific to Firebird and Camaro.

QwkTrip

iTrader: (22)

I can see how that would be confusing to somebody.

ratfink is correct, F body is the vehicle platform for Camaro and Firebird,
https://en.wikipedia.org/wiki/General_Motors_F_platform

I might be wrong, but I think the bits and bobbles of the C100 connector are the same for all 82-92. However, the wiring pinouts vary and that's where the wiring schematics come in handy.

Devin85

Yes, I’m aware it’s the F Body platform.

There are differences, that’s why the pinouts are handy and why I’m asking to see if anyone knows of a 1985 Firebird specific pinout or if it was indeed a common wiring scheme for 1985. Just wanted to be sure before I started cutting wires.

John in RI

iTrader: (167)

Most of the C100 Diagrams on my website came from the factory HELM shop manuals for each year & body that I had a physical shop manual to cover. There are a couple I used that were found on the web - but not many. 87 Firebird is an example; I don't have that manual but found that specific diagram somewhere else and used as it was specified as being accurate for 87. ) Sorry - but I don't have the 85 Firebird Shop manual.

Devin85

Thanks, I’ve started tracing my wires and I’ve found that the 1988 Firebird is very close to my C100 pinout, only a few differences.

Berlinetta.info is your website? All my references I’m using are from your site. It’s fantastic you complied all that info together and share it with everyone. It’s been immensely helpful to me in this nightmare of wiring I’m dealing with. It seems to me that GM made this birds nest way more complicated than it needed to be, especially with how they spliced multiple connections together. Distribution blocks and bus bars would have made things so much cleaner.

At this point I’m pretty much just custom wiring everything to my own design and re-pinning C100 with a new connector. Drawing up my own electrical diagrams to go with it too. Im just worried about getting all the gauges to work correctly, that is going to be the most difficult part I think.

John in RI

iTrader: (167)

Yup,... I made the site sometime around Y2K and it's been up ever since. It's a bit out-of-date, just never seem to have enough time to update it properly !!!

I would have guessed the 86 or 87 Firebird C100 would be closer to your 85,..............

Getting the gauges working will probably be a lot easier than you expect. Just about all the gauge wiring is located on the ENGINE section of the C100 harness. If there's one thing I think some of the schematics got wrong is the wiper wiring. IIRC starting in 88 the Wiper motor wiring moved from the ENGINE section to the HEADLIGHT section of C100, but most diagrams still show it on the ENGINE section till about 90. If your 85 is a TPI than the oil pressure wire might cause some anxiety too; it comes off C100, but then plugs into a connector on the ECM harness, and then it leads to the Oil Pressure sending unit plug. ( so while the tan wire starts at C100,..... it ends on a 2 wire plug to the ECM harness,..... not a plug that directly connects to the sending unit. )

Because of the changes to the Firebird headlight system from starting in 88 (or was iit 87?) be sure to follow the earlier schematics when dealing with the HEADLIGHT section of your C100..... unless your gonna' convert to the 88+ headlight module system. Good Luck !!!