i have 85 firebird and 140 mph gauge cluster from a 91 i need to knw if anyone knws which wires to splice together to make them work i already have the electronic speed sensor on the trany

 

compare this
to this
and go from there

 

the diagram for the 91 helps alot is ther anyway u can get the gauge diagram for the 85 because they cut the connectors so i dnt knw what the wires go to

 

if they cut the connectors, then a pin out isnt gonna help you. just go by wire color.

on a side note, youll need a vss buffer box since the vss signal was sent through the ecm on the 91 and then the buffered signal was sent from the ecm to the speedo. a 90-92 305 tbi will have one you can use.

 

yea i just trased all my wires with a ohm meter and used the pin out to tell me where to hook them on the gauges still gotta hook up the speedo and when i hook the tach wire up the motor looses fire