I'm really in need of help on this. I put a SBC V8 in a 94 S10 pickup with an early 700r which we installed the electrical speedo setup which worked great.... for about 200 miles! I hired a place called HeyMike in Hayden Idaho to do the work. It sat for about 4 days and when restarted the speedo was dead. An outfit in Kent, WA checked the speedo twice and it was ok. The 'drat' which is supposed to be the VSSB/VSSM was changed out three times and that made no difference. The thought is that the dead short could be the cause but we cant locate it. Sometimes it will go dead over night, other times it will be ok for 4or 5 days starting right up. Some symptoms are the dash lights dim when the headlight switch is turned on, the gauges will fluctuate when the headlights are turned, twice the speedo needle jumped to abut 30mph, but not sure what we did to make it happen. We installed additional ground wires from engine to frame and body to frame to engine trying to chase this but it like a ghost! ANY help would be eternally appreciated!
Hopefully, I have done something stupid and can't see it! My college professor is probably rolling over in his grave wondering what his prize pupil has done to his hotrod!