Posted this once in what I believe is the wrong section... So heres the second attempt....


Hey, whats going on guys, Im Ryan. Been searching this site for the last few months along with sites like Ls1tech and things of the like. Finally decided to join the fold. I've wanted a firebird since I was a little kid, fast forward 20+ years, and I was able to get one...For free nonetheless, that had been sitting in a garage for about 10 years, so rot is minimal (basically none). It actually belonged to a buddy of mine back in high school, so thats pretty cool. I'm no stranger to large projects when it comes to vehicles, but this one is particularly exciting for me.

Now, onto the topic at hand.

I'm in the parts collecting/reading portion of my LQ4/T56 swap for my 87 Trans Am. In the last month of so I've probably spent around 60 or so hours just scanning threads, reading reviews, picking which part I think would best fit my particular application with my LQ4 build, figuring out what wiring I'll need to do.

I've got at least 60% of the parts I need, and have most of my electrical figured out, but the one factor that I've been unable to find info on is how the factory digital dash in Trans am wires up to be used with my LS swap. I've tried the search button on just about every forum I've come across, but havent been able to nail down that bit of information.

Anybody know what needs to be done? Is there a write up I haven't found yet? Is it even possible to use? Any help would be appreciated.

 

Should be the similar as an analog gauge setup. I have a Helms manual for the 88 Firebird.

The oil, tach and water temp should come through the C100.
The Speedo comes from the VSS buffer but the VSS wires go through the C100 according to the manual, so you'll have to bypass the buffer and wire to the correct output to the dash
C207 has a bunch of grounds for the dash, so you'll have to add them

 

Not that I would know but my 87 has a tpi motor and with the ls swap everything worked just the same. The only issue as far as gauges go is my speedo. That does not work but if I hook up hptuners it shows that it's working. The guy that I would guess that would have the answer is Pocket. He's usually on ls1tech but he does make harnesses for the swap so I'd guess he would be able to answer your questions.

 

As the owner of a GTA that originally had the factory digital dash, the answer is it wires up the same way an analog system would. The input signals are the same as the analog dash so you just have to find the right wires and connect them to the signal source. The LS ECM can output a tach and speedo signal. You can also get oil pressure and coolant temp from there. Fuel level is unaffected by the swap if you keep the factory tank and sending unit.

That's the easy part. The Drivers Information Center in the top center of the dash, has it's own sensors. The only one that you might have an issue with is the coolant level sensor if you swap the factory radiator for a different one that doesn't have the provision for the level sensor.

Be careful when working with dash related wiring. It is easy to short the circuits in these if you aren't careful and they can't be repaired and no one makes parts for them. Once you break a gauge, your only option is to find another dash and scavenge parts off of it.