Hey everybody, I need some ideas. I have a 93 4x4 5speed truck with a bad PCM. I NEED to get the speedo working. Finding a working pcm is out of the question so I'm trying to do the bypass method I read on here.. I've tested the VSS (2 wire type, with no voltage supplied) and it opens/closes the circuit as it should. I've ran a wire from the VSS to the green signal wire on the back of the speedo and ground the VSS straight to the NEG terminal on the battery. No better ground than that right?

I can spin the VSS with a drill and I get no speed reading on the speedo at all. Speedo head IS getting its 12v supply with key on.
If I test my VSS for some kind of voltage output I also get nothing, is it supposed to put out any voltage when spun up?
If my problem is the speedo hardware itself, what should I look for?

Desperate to sell the truck, I'm in some financial dire straits. But no one wants to buy a truck with no working speedo and odometer.
Thanks for any help

 

Where are you located?

 

Sunny San Diego

 

Why do you want to try and fix this in a more difficult way than just replacing the PCM?

 

Did you sell the truck?

 

the issue likely has nothing to do with your pcm and likely 100% the gear in the speedometer in the dash. some plastic gears age better than others but should not require the pcm to run. i hooked up the speedometer out of a 91 in my 81 just to see if it could be done and it can. the pcm only need speedometer signal to run stuff like cruise control and overdrive.
https://www.dieseltruckresource.com/...r-long-128685/