I have a 95 tahoe and ive been trying to intstall rostra electric cruise control unit #250-1223. The switch is #250-3421 The problem I have is the vss wire hook up. I have found the wire on the digital ratio module its green and white. I jacked the rear of the truck up, put the unit in diagnostic mode and as I spin the tires the unit does nothing for a few seconds. Then it starts to flash about once every second continuously no matter how fast I spin the tires, even when I stop them. While in dianostic mode i have checked everything else, the tach and the switch also the brakes all work. I found the wire to the vss on the tailshaft of the truck, one was green and black the other purple and white. I spliced into both with the same result as hooking it to the orignal green and white wire. I have the switches set up for 4000ppm. I could really use some help.
try looking for a two wire harness plugging into your transmission. when ever i can't find the VSS wire inside the car that's where i check. also try calling the company whre you purchased the cruise control moduel. most of the time they will offer some type of tech support.
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life is a comedy to think, a tragedy to feel
well I meant transmission when i said tailshaft, and i tried Rostra number and was on hold for 35 minutes and finnally gave up. But I will keep trying to call, just thought I would post this for any help.
You vss wire is GREEN / WHITE pin 50 of the ecm in the engine compartment drivers side beside the engine. If you unsnap the computer and lift up pin 50 of the exposed plug wiring is easy to see without taking anything apart on the computer.