Ok, i know this topic seems to have been done to death, but i just have a few questions. Ok, i read a few posts and got some idea of what to do but im still a little lost. I have a 88 Iroc, TBI 305 car, and i want to put the entire dash setup into it from a 92 RS i have. I already pulled out the dash from the 92 and ALL the interior wiring(from firewall connector to taillights) and all that will be going into the 88 Iroc. Now what do i have to do to get the VSS to work? how is the VSS harness connected to the Speedo itself? Does it run through the ECM? This IS a 6cyl 92 RS, so no TPI. and i remember someone saying non tpi cars have a "buffer box". If that box is inside the car/dash, It will be swapped into the 88. I also need to know if i can connect the Stock 88 Engine harness through the firewall connector to the stock 92 interior/dash harness, and will the gauges work or do i need the complete 92 engine harness? I have the 92 still with the engine compartment untouched so i have anythign there i'd need. I know enough about wiring so i can rewire whatever i need, i'm just a little unclear of the differences between the 82-89 style over to the 90-92 style gauges. Any help would be greatly appreciated. Thank you. -Paul

 

ANYONE??? i traced the 2 wires from the VSS, one goes to the dash, the other goes into the harness towards the ecm. How do i hook it up without the ECM? I'm gonna check with the wiring diagrams today. I think by the time im done with this post i'll answer all my questions for myself...

 

ok, to my dissapointment, i found out that the 6cyl has the buffer for the VSS in the ecm just like the TPI ecm, so now i need a Buffer Box.... Where do i get one, i dont have any junkyards near me, and how much are they? That sorta solves the vss issue... next step.. swapping in a 88 TPI system... now should i just convert to speed density and get a 90-92 comp and harness and i'll be all set. i got a lot to think about...thank goodness time is not an issue. any help/advice would be appreciated

 

Im very sure you cant just plug n play with the older harness, one of the main things being that the early ones had the wiper hookups in the engine harness and 90-92 cars have it in the headlight section, so theyre on opposite sides of the bulkhead connector, you'd be best off getting a 90-92 engine harness.

 

ah ok i didnt know that about the headlight section of the harness being changed, however i did pull the headlight section of the engine harness from the 92 RS and i was gonna use that anyway, now i just know i have to, lol. i just need to find the tpi speed density harness and everything should work easy. one last question... how different is a auto vs manual trans harness? cant i just use a prom for a 5spd and leave the tranny wires disconnected. VSS i already have from the 92.