M2004SCMC

I've got a 95 Trans Am that we converted to electric when the motor gave up. I'm having some trouble getting the guages to work. If I recall correctly, shutting the engine off and coasting dropped the RPMS (obviously) and the speedometer to zero. My guess is that the PCM only converts the VSS signal and sends information to the cluster when the engine is running.

Assuming I'm right, is there an input I can apply voltage to and trick the PCM into thinking that the engine is there are running? Other than that, it seems that Dakota Digital has little black boxes that I could use to wire the VSS thru and bypass the PCM for both the speedometer and tachometer, but at a cost.

The car is a manual transmission and the A/C will be controlled by an aftermarket computer so I don't think I need the PCM for anything other than speedometer control. If this isn't an easy fix it may be worth getting the Dakota boxes and removing the PCM and it's gaggle of wires.

Thanks,
Mike

Injuneer

"Converted to electric"...... as in an electric motor. OK

In that case, retaining the PCM makes no sense at all. The Dakota Digital SGI-5 box will convert the VSS signal to the signal format required by the speedo/odometer. The box includes a bunch of DIP-switches that allow you to adjust for gear ratio and tire diameter. For details of the various trans pulse counts, and the details of the VSS on various years, go to the "jagsthatrun" site. They are real big on installing Chevy drivetrains in place of their English boat anchors.

If you can figure out how to run the Trans Am on batteries.... I would think that figuring out how to drive the tach (whatever the value of that info is) would be a piece of cake .

MikeGyver

Interesting project, what motor are you using?

M2004SCMC

Thanks. Sounds like the SGI-5 box is the way to go for the speedometer and I suppose their similar box for the tach. It's still useful to know how fast the motor spins up, "redline" is about 5000 rpms for it.

I used a WarP11 from Netgain. It's a 11" diameter DC. Given the weight of the Trans Am I wanted to be sure it kept some grunt. I use a 156V pack and a 1200 amp controller so it does ok around town. Right now the suspension is wheel hopping real bad if I give it too much throttle. Hopefully some parts will fix that an it'll be a tad quicker.