95 TBI into older 4x4 vss question

[1BadAction]

Use a cable to VSS converter. It will screw into the fitting on the tail shaft of the T-case and the speedo cable will screw into it. That will send a VSS signal to the ECM, while still allowing your cable driven speedo to function.

You will also need a way to tell the ECM that the truck is in low range, usually it's a switch to ground on the shifter. This may be where the DRAC comes into it, but I only know the later ECMs that just used a direct input.

[dale]

1bad, thats what I was talking about I need to buy. But they come in different pulse settings. I would like to get the right one the first time.

[buddrow]

Should be 4k ppm. The DRAC is the "signal conditioner" from the vss to the ecm/pcm/ instrument cluster. Note: your speedo could be off as much as 20mph depending on your setup.

[dale]

So what your calling DRAC, I'm calling VSSB?

Oh, i'm sure its gonna be off. Different tire size, different axle ratios. But just getting a signal is my first step.

[1BadAction]

So what your calling DRAC, I'm calling VSSB?

Oh, i'm sure its gonna be off. Different tire size, different axle ratios. But just getting a signal is my first step.

Yes, blame GM for that one, lol. They called them DRACs or VSSBs in different years and models. Most people with TBI vehicles seem to call them a DRAC.

[EagleMark]

The "White Box"

[buddrow]

Yes the vssb is also known as a drac module. Thats what i learned at as. And vehicle speed is kinda important to proper fueling and spart timing. Trust me on this. Had a pickup that would stumble and or die when coming to a stop, fixed the vss signal and all is well.