1993 OBS Speedometer and Cruise Control wiring

[LS1GMCTruck]

Would a '96 have a DRAC and a VSSB? Or by '96, were they built into the engine computer itself?

[GasGuzzler]

The 96 has a VCM instead of an ECM and the VSS goes straight to it. From the VCM, the VSS signal goes straight to the speedometer.

[Chevy-Art]

I've been running around with no cruise for the longest time so I thought I'd get around to fixing it. The answer was very simple with help from GasGuzzler. Remove the white DRAC box behind the glove box and pitch it in the corner. Cut the light blue wire with black stripe. Cut the red wire with white stripe. Take a butt connector and stick the two wires in one end and crimp. Take the speedometer signal wire from the PCM and crimp it to the other end. Job done.

BTW, the cruise control cable I used is from a 1998 C1500 with a Vortech V8.

I was wondering how I was going to do this, and also what cable to use.

[LS1GMCTruck]

The 96 has a VCM instead of an ECM and the VSS goes straight to it. From the VCM, the VSS signal goes straight to the speedometer.

Oh...o.k...a VCM...lol. What the heck is a VCM? lol Where would the VCM be located? I had this small black box mounted to the inside of my frame rail, that I never knew what it was. I discarded it when I did my engine/trans swap. Hmmm...

[GasGuzzler]

VCM is vehicle control module same as ECM or PCM depending on year and function.

[RedHeartbeat]

had the dig the DRAC unit back out of the surplus parts pile and hook it back up. It seems the DRAC unit is part of the brake system electronics. My brake light on the dash was on without the DRAC unit installed. I'll see tomorrow if the light went away.

[DBRODS]

had the dig the DRAC unit back out of the surplus parts pile and hook it back up. It seems the DRAC unit is part of the brake system electronics. My brake light on the dash was on without the DRAC unit installed. I'll see tomorrow if the light went away.

just take the bulb out of the cluster...

[92 6.0]

I was wondering if anyone has the wiring diagrams for the cruise circuit. I hooked mine up just as the instructions stated but it still don't work.

[RedHeartbeat]

First thing to check is the power and ground leads at the control box. Send me your email address address and I'll fwd you the diagram.

Check the funtionality of the cruise switch while you have the cruise box unplugged. Put a multimeter on the leads and look for 12v when you press the control buttons on the steering column.

Your speedometer is working, correct? You did disconnect the wires in the top from the DRAC module and didn't just splice into them, right?

[92 6.0]

Yes my speedo is working. I cut the wires and spliced them in to the vss output of the ecm. My cruise never worked before the swap but I thought it might have been the faulty brake switch I found when I was wiring up the tcc wire.