I'm putting a fastback on my 88 coupe today and have run into this. All of the tail lights work except the brake lights. Third light works, all fuses are good, all bulbs are good. I can plug the old coupe harness back in and the brake lights work so it is not the switch,fuses, etc. The fastback harness brake lights work ok if I apply power to it using jumpers. Is there some other jumper or wiring modification that has to be done to get the brake lights to work. TIA

GT brake lights get there feed on the white wire. Which you will have to spice into the white wire coming off you brake light switch at brake pedal under dash. Cut the signal from this wire to signal switch in column or you will have amber lights lighting too.

Let us know if you need schematics e-mailed

Do you need to run a wire from the brake switch all the way back to the breake lights.

Yes, a schematic would help.
paul@phoenixhobbies.com
Thanks

scanning pics for ya

scanned-sent.

[This message has been edited by PBJ (edited 06-30-2001).]

I explained this in an earlier post (a few months ago)
search a topic with the same name as yours by alex2001

PBJ, got the pic's thanks. Tried what you suggested and it works great! Thanks alot and have a good weekend.

Does anyone else have the schematics on how to do the fastback wiring? I dug this up outta the archives search.

Thanks!
Sean

One of these days I'll get this posted to the cave.....

In all cars built after introduction of the separate brake and turn lights..... (Should be all 86 and up. may be 86.5 and up. Never can be sure when Pontiac made certain changes. It might even work on some 85.)

You should not need to wire all the way to the dash during a fast back conversion. You can make all the needed connections and changes at C500, which is right by the battery nice and easy to get at.

C500 was built to automatically select the correct wiring based on which rear light harnes is plugged into it...

The fastback brake lights, which feed from the same wire as the high mount brake lamp, and are also light blue wire.... connect to C500 terminal J9

In coupes... there is a white wire shunting between C500 terminals C7 and H8. Cut that wire to disconnect the brake switch from the turn signals.

Alternatly you can connect the brake lamps to the C7 side of the selector shunt you just cut. This saves crimping terminals you if you cut the harness from C500 in the donnor car.

This info can also be used when wiring modifcations like sequential turn lamps.

All of this is right out of Haynes and ALLdata. Page 289-290 in my Haynes book.

Since you have the harness connectors... check the above terminals. Specifically J9 on the body half to make sure that it's both wired, and getting power when the brake pedal is pushed. If for some reason it's not wired then try C7. The terminals can be released and moved. Move the J9 terminal to C7 on the lamp harness connector.

[This message has been edited by theogre (edited 12-16-2001).]

Theogre,

This is an 85 conversion. I see a junction box right next to the battery and has fusible links wired to it. Do you have a diagram scanned somewhere? Can these wired pins be moved on an 85 year Fiero??

thanks,

Do the search under alex2004 about the fastback conversion wiring! LoL...I did the conversion on my 84 SE w/ no new wiring harness. just bought 4 single filament sockets and did the entire wiring process!

Alex...

I've no idea how it's factory wired for pre fastback years. If they don't follow what's in hayne's book I ain't got it. This thread was started by someone doing an 88 car....