Meinherr49

I was just wondering if anyone here Tried to put Trans Am Checkered Tail Lights in a Formula with the Standard Firebird Tailights . I have 88 Trans Am Tailights and I am Trying to put them in my 88 Formula . The Turn Signal Bulb in the 88 Formula Tail Light is only 2 Wires , Black and Brown and is Just A Single Element Bulb , whereas the Trans Am Turn Signal in the Tail Lights is a 2 Element bulb with a 5 Wire Bulb Socket . How could I do this MOD ? Anyone know ? I have a 88 Trans Am Tail Light Wiring Harness , but it will not Wire Up Right in the Formula . I was thinking I could Splice the 5 Wire Bulb Socket into the 88 Formula Tail Light Harness somehow .


This Post has been Amended for Errors . The peanut Bulbs mentioned as a Turn Signal Bulb was incorrect . The 4 peanut bulbs in the 88 Tail Light Harness are for RUNNING LIGHTS ONLY . I hope this clears up what i was trying to say ,.........Thanks

Slinkoguy

iTrader: (1)

TRANS AM HARNESS WILL NOT WORK!!!!!

Slinkoguy

iTrader: (1)

Cut off the 4 "peanut" bulbs located in the middle of the harness, wire a dual phase socket on each side in place of the single phase sockets(the sockets on the far left of the tail and the far right). Black to black, splice brown into the brown wire from the socket beside it, and match your 3rd remaining wire to the remaining wire on the harness. This gives you all 6 lights on for running lights at night (just like TAs have from factory), and makes the outer most lights on each side your blinkers, and the other 4 red lights your brake lights (just like factory TAs). Hope this helps!

89FormulaRoth

iTrader: (1)

Sorry to rehash this issue again, but I've searched and searched on this issue and was unable to make it work. I'm want to learn, but I think I've gone about as far as I can by myself without asking for help. Since this method made sense to me, I gave it a shot. I followed the instructions above as I understood them.

I did this to the driver's side only. What I did was leave the two combination running/brake lights alone. Those became my two middle sockets (between the reverse light and the turn signal). I cut off the original turn signal socket and using a two phase donor socket from a TA, I connected yellow to yellow and then connected the brown and black wires from one of the "peanut" lights. (The donor socket had only one yellow, one brown, and one black wire coming from it.) I left the other peanut light disconnected. The ground from the original turn signal socket was also left disconnected.

When I tried it, my running lights worked, my brake lights worked, but my turn signal did not come on at all. I tried the hazard lights and those worked, though. I thought maybe the turn signal switch itself might have gone bad (highly unlikely since I'm messing around with all these wires, I thought, but what the heck) so I reconnected all the wires/sockets (just by twisting them back together) and tried the turn signal switch again. Still there was no turn signal light. I realized that I didn't have the ignition switch in the "run" position, so I put the ignition switch in "run" and tried again. This time, both turn signals worked, but would stay on constantly instead of flashing. One of the "peanut" bulbs was burned out if that makes a difference.

Any ideas of where my mistake was? I'm not interested in cutting new sockets into the tail lights if I can avoid it. I want to understand the wiring better. Thanks!

Meinherr49

In order to do this Mod , you must first Forget and Tie Off the Peanut Bulb Light Sockets and Wires , they are not used when you change over to the Trans Am Tail Lights . All that is needed is a FIVE WIRE 2 Element Bulb Socket that is spliced into the Present Tail Light Wiring Harness . The Socket is used 2ND in from the end of the Tail Lights . That Socket will then become your Break Lights . Hope this helps you out .

89FormulaRoth

iTrader: (1)

Okay, I understand that the peanut bulbs have to be terminated and I understand that I need to use the five wire two phase socket from the donor harness (two yellow wires, two brown wires, and one black). What I don't understand is how and where to connect it. I'm sorry, but I don't fully understand. Am I leaving the original turn signal socket alone or is that the socket you are talking about? What wires go where?

HCR13

iTrader: (5)

I think you need to seek the help of BigBabyLou or Stephen... They can definitely help you out...

89FormulaRoth

iTrader: (1)

Thanks! I'll do that.

BigBadLou

iTrader: (3)

Hey guys, glad I caught this thread.
If you want to install GTA tail lights in a Formula and make the tail lights work exactly as on a GTA (i.e. with the brake lights and turn signals integrated), you will need to make a small wiring modification under the steering column. I am currently writing up an article on that.

Otherwise, what you could do is to use let's say two red lightbulbs in each GTA tail light for brakes and one for the turn signal (because they are separate wires on Formulas).

Do NOT, under any circumstances, splice the wires for brakes and turn signals together. This will NEVER work and will only create more problems.

I will post an article on the tail lights swap shortly and announce it here.

Lou

BigBadLou

iTrader: (3)

Ok, I finished the writeup.
It's on our ATGO site in the Tech Article section here:
http://www.austinthirdgen.org/index.php?pid=37

Hope this helps.
Lou

HCR13

iTrader: (5)

89FormulaRoth

iTrader: (1)

Thanks, BigBabyLou!

Stephen

iTrader: (12)

Thanks, but I'm NO WHERE near the level of BigBabyLou. He's the OPEG I go to for help.

HCR13

iTrader: (5)

haha, I guess I'm on the bottom of the food chain then...

89FormulaRoth

iTrader: (1)

Thanks again, fellas. I've finished my swap and I'm pleased with the results. I've got it set up so that the two outermost lights act as brake and turn signal lights. I thought about making all three on each side act as brake and turn signal, but I'm running out of time to get my car on the road, so I had to stop screwing around. The hard part of this swap (that I couldn't figure out myself) was the under dash connection, but it all makes sense to me now with the help from BigBabyLou. Now if I can just find a center section...

BigBadLou

iTrader: (3)

Btw, I have been notified that some base Firebirds out there don't have a splice on the blue wire but rather they are wired "from socket to socket". I added another picture to the tech article to account for that.

Hope this helps.
Lou

HCR13

iTrader: (5)

Thats how mine was, but it was no problem, I figured it out pretty quickly...

89FormulaRoth: Now you should get Sequential turns signals!
haha

allgood

can you help me what are the appearance diff. between a 92 trans am and 92 gta besides the outside badges.

88FormulaKiller

iTrader: (8)

i know this is old but i thought this might help out, i just swapped in 88 grid TL's into my 91 formula and i all i did was swap them in using the existing harness. i took out the small 094 bulbs instead of cutting them and set them aside(tape'em to the back of the housing, you will never see them) and just plugged in the other four 1157 sockets accordingly. there is only 2 small issues if you do it this way, the blinker socket will not fit against the body inside when you try to install them(this may only happen with 91/92 styles-im not sure), i modified mine slightly but cutting small squares to allow the sockets to slide into when the light was installed and the blinkers will only be blinkers, not running lamps/blinkers. IMHO and the opinions of friends, only having 2 running lights / brakes lights looks alittle better than having the hole thing lit up. hope this helps someone out there.