Anyone know why a 92 Z28 with a 700r4 automatic would have a dash light that comes on prompting me to shift - even when the car's in overdrive. RPO codes show the car's a factory auto and the VIN indicates an L98 350 so it must be an original automatic. Did automatics come with shift lights or should I be doing more research on the car's history? It's supposed to be an all original Heritage Edition 25th Anniversary model. The only modification the car had when I bought it was 3.73 gears - I have installed Richmond 3.23 gears and the light still comes on. I expect that I could just remove the bulb - But I'm more concerned about whether the car's an original 350?

 

do I search, it has been discussed before. I just can't remember the answer.

 

Automatics didn't come with the shift bulb installed, but if you put one in it will light up when the TCC locks.

 

Thanks - I had tried a search but got thousands of hits - I tried to narrow the search & still got 100's - & several different answers. These are the best (I'm not sure what the 2nd one means?)

The instrument clusters are the same on all cars, manual or automatic. The autos don't get a bulb, but are still wired to the ALDL and ECM like the manuals. If you put a bulb in you'll have a lamp on your dash that tells you when the torque converter clutch is locked up. Too bad it says "SHIFT" instead of "TCC".

Actually, the '90 - '92 ECMs have two separate I/Os to control the TCC & the shift light. The earlier ECM style used a single I/O to control the TCC & shift light.

 

Neat. Initially, I figured it would have been because of a manual trans PROM being installed.

 

I know this may sound dumb to some people. but does anyone know exactly HOW to replace this bulb? I know its wierd but I want to put a bulb in mine, I tore my cluster out and STILL didn't figure out how to get to it. pics would be fabulous if anyone has any for some reason.

 

The bulb holder twists in from the rear.

 

I knew that, but I couldn't seem to find the one for the shift light, there wasn't one directly behind it and I couldn't find one that lines up with it. i will tear it appart again today and see what i find.

 

If you have an automatic then there's no bulb or bulb holder installed at the factory.

 

really...well I found it and it works now..thanks

 

The Firebirds have a place to put a bulb in, I'm looking at two clusters right now that can have the shift light bulb put in, and they both came out of auto cars, they just didn't have the bulb in it.

 

THANK YOU! I knew I wasn't crazy.