I've searched for about an hour on how to do this and cant find exactly what I want.


Okay, I have stripped my car of its computer in anticipation for my new engine. I have made a new wiring harness for all my other gauges except for my speedometer.

I have a 1987 Firebird with an electric driven speedo. I found the two wires on the tranny which i'm assuming is for the speedometer, but do they go directly to the speedometer, or do they go through the ecm? If so, how do I keep my speedometer working without my ecm?


I found a couple things on something called a "speedometer buffer" or something. But I dont know where that is or what it looks like.


thanks for any help.

 

The VSS buffer module is strapped to the back of the ECM mounting bracket. (the big yellow thing):

 

alright so if i just leave the buffer plugged in, the speedometer will work by itself without the computer?

 

On your '87, the VSS is mounted to the transmission. The speedometer does not need the ECM to operate (unless you have a digital dash Belinetta or GTA - NOT in 1987), and the VSS pulses are fed to the speedometer as well as the buffer box.

If you have a cruise control and intend to keep it functional, the brown output wire from the VSS buffer box runs to the ECM and the Cruise Control Module. You'll need to keep that wiring intact.

 

alright...that makes sense. Thanks alot.