Hey guys whats up. Got a question. I just installed an 96 lt1 in my 91 camaro and i wanted to know about the wiring. i know there is a post on thirdgen and i have read it a hundred time and i'm still reading it. My question is were did you connect the wires? Do i pull all the old wiring out? Do i cut a hole in the fire wall or do i hook it up under the hood? And the one's that say for example (orn power feed from ecm bat fuse #4) do i have to splice in to the ecm or is to this the fuse box under dash need some help thank's

 

By far the easiest solution is to use the 4th gen Underhood fuse box. Pretty much all of the fuses needed for the PCM wiring harness are located in that.

The other way is to use the existing fuses under the dash. All of the ones you need will go through the firewall at the C100 connector. For example, the PCM Ignition feed coming into the LT1 PCM on B30 and D3 is hot when the key is on. Connect this to F4 on the C100 connector as it was used for the same function on the 3rd gen. Things such as the fan and fuel pump relays are all ready tied into the circuits going through the fuse block, the only thing connected to them is the ground from the PCM to close the contacts. The only thing I can think of that wouldn't have a fuse under the dash is the PCM Battery feed on B15 and B31. Easiest solution for this would be to run a wire to the underhood distribution block and have an inline fuse holder.

Tristan

 

I don't have a 4th gen fuse box. I'll use the one i have on my third gen. So it's all basicaly wire to the fuse box and to gage cluster? Did you take your c100 connecter out or did you splice throw it? I was getting PO trying to wire it the only wire i found was the fat purple one for the starter. Even with that one i wasn't sure where to splice. like i said i read the lt1 posting with you mat89rs and multi-tasking. I got a 91 sevice manual and the info from you guys. I want to make sure i don't fry anything. TexasLT1 i emailed you about the t5 hook with the 4th gen. how did you hookup your vss to your t5. TexasLT1 thanks for your help


:hail:

 

Just wire through the C100 connector. Check out the link on the TGO main page to the wiring diagrams, in there is a diagram of the C100 connector, should help out some.

Sorry about not replying to your e-mail, I havent checked it lately. Currently I am running two VSS's, the stock one is untouched and drives the speedo, the new one drives the PCM. What I will end up doing though is getting rid of the stock one all together and using the speedo output from the PCM to drive the speedo.

 

Did you use the vss from 4th gen or is it after market.
also what did you hook your speedo and vss to? did you use
your stock connecters? How much of your old 3rd harness did you get rid of?

 

I actually got a VSS from a newer S10 I think, then mounted a 17 tooth sprocket on the driveshaft.

Speedo and stock VSS remain untouched. New VSS connects only to PCM.

Pretty much all of the old ECM harness was cut out. About the only thing left was the guages, fuel enable, and VATs wire. Not much else was left.

 

Thanks TexasLT1 I'm going to try again tommorrow wish me luck.
I can't wait to fire it up!!! keep you posted if any problems.

 

Alright i got the fat purple wire tan,white,green connected but i'm stuck on the ign pink. i've been working off the bulk 100. That pink wire is ign (f4). those the pink from white connector (E) power feed from pcm ign fuse 13 and the pink from blue connector (G) power feed from engine sensor fuse 10 and also the c 100 that is on the lt1 (G) power feed from ign fuse 11 obdll
are these going to be spliced together? And the fuel pump relay the red fuel pump prime connector and blk/wht ground wire does it go directly spliced to the relay? any help thanks