GMC TopKick VSSB DRAC "Reprogramming"

Hi guys. I have a 1993 GMC TopKick C6000 with a 366 gasoline engine. It was a low-pro truck with the 19.5" wheels, and I not only put 22.5" wheels on it, but I changed the rear gears from 4.63 to 3.36. Needless to say, the speedometer is way off. Now I understand the "conventional" older vssb/drac where you replace the jumpers with dip switches, but this vssb/drac is completely different. The harness connector is different and there are no jumpers. It looks like it's just a bunch of resistors. Im not seeing any way to access it through the computer, and Im told that this is a heavy duty (c4000 and up) vssb. I've done quite a bit of homework on this topic and cant seem to find much at all. Any help would be greatly appreciated. Thank you.

Those resistors are probably fuses. Take a VOM and measure each one. I'd bet some are open ( or high resistance compared to others because they are in circuit).

HTH,
Brian

Ok. Thanks. Ill have to play with them. I have an extremely odd driveline configuration.

Hi, I also have the same truck as you! I'm working on converting mine into an RV. I was wondering if you know what I can use to do some data logging with this engine. What software can I use. I'm not interested in tuning at this this point, just data logging to sort out some knock sensor and other trouble codes. any suggestions would be great! thank you, Dan