Ok guys im swapping from a CC carb to a TPI setup... I have an 86 trans am, and im getting the wiring harness and everything out of an 88 iroc. Now... this harness dosent have a provision for the VSS and i need my speedo to work. Is there a way to make it work without changing gauges? I read somewhere that if you use the buffer box, and run power to it, it will work

 

I'm not sure what the VSS is. Is it Vehicle Speed Sensor? I don't know. I have a 89 Formula that has a TPI setup and it doesnt have anything like this. Or maybe it does and I dont know what it is.
Anyways I put this 89 harness engine TPI combo in my 87 Base model Firebird. And everything switched over fine to my original 87 gauge face. I decided to change the gauge face later to a 160 mph speedo and it transferred fine.
I guess the problem might be that the 86 gauge face you are using is cable controlled not electronic? I'm not sure if thats the case for you but for me it was an easy swap.

 

my gauge cluster is electric... The Iroc that i got it out of was not however, so i need a vehicle speed sensor, or vss

 

Ok im looking at the wiring diagram right now and its showing that the brown wire from your vss goes to the ecm. So if your 88 harness doesnt have the provision in the ecm then i think you are screwed.

 

The buffer box signal is an output from the speedometer to the ECM.
On my 88' The VSS is not a module it's part of the instrument panel printed circuit board. The ECM and the CCM (Cruise control module) require this signal.

 

Yea im looking at the diagram right now and i think that the ecm just tells it when there is a problem with the vss or the buffer.

 

Using the vss from the transmission there are two wires going to the vss buffer. yellow and purple.
The power wire is pink/black. It is a 10 amp fused power wire.
The red wire goes to the cruise control but turns to a brown wire when it gets there.
The blk/wht wire is your ground.
The one important wire your may have to mess with is the lt grn/blk wire. This one goes to the instrument cluster printed circuit.
Then just leave the brown wire for the ecm off. Try that!

 

I dont know if this will help at all. But there are two connector faces to the gauges. The one that is labeled C1 is the one you want to use. Use space number 14 which if you are looking at the connector face is top row last one on the left. Hope this helps dude! Light Green/Black!

 

lol... ok huh? Tell me if im right... i want to look at my wiring harness in the car now? and find c1 then do what?

 

Steve:
Come by my shop and I will show you what you have to do.


Don>>>
1207 W. Struck, #E
Orange, CA 92867

 

don... i might after i get it running, but it wont be for a while, cause i have school during the week, and i work on the weekends, what time/hours are you open... and should i bring the ta or is it cool if i bring another car?