T-56 Transmission Install Thread
Technically I could buy a CableX from Abbott industries (or something like that) which is exactly what I'm trying to build in a way. It's just a box that takes a VSS signal in that you connect the factory cable to if you want to run a mechanical gauge. I think the Viper unit is an open collector design. If you look at the factory wiring it's a bit odd as it has both 9v and 5v going to it on the harness when I checked my mom's 94 Viper. I think it does it this way for sensor error checking though. Something like it expects to see 5v at minimum to make sure the sensor is present, but reads the higher 9v signal as the actual pulse. That being said, it doesn't mean you have to run it that way. I've tried powering mine just about every way possible and I just don't get enough signal out of it, so I'm guessing I might have fried it from wiring it wrong or giving it too much juice.