I put my foot on the brake. So, I have an 84 with sbc and the speedo won't work unless I put my foot on the brake. The minute I remove my foot it drops back to zero. The odometer is working and the radio fuse is good. The cluster was just resting in position because I have my interior torn out. On one of my test drives it did short out and I had to replace the fuse. I do beleive that is around the time it stopped working. It would work sporadically with out the brake and now only with it. LOL
The gear is still attached and the wiring seems secure everywhere. The only thing I can think of is a ground problem and the actuation of the brake is completing the circuit some how????????? If any one has any clue I would appreciate the help, Ray
I was hoping to get some help with this because speedo still isn't working. UPDATE: So besides working while my foot is on the brake my speedo also works when I turn my lights on!! So is there a common wire in or around the cluster/column that these all share? Maybe a ground wire?? Where does the ground wire for the speedo actually ground at?? Your help would be appreciated, thanks Ray
Sounds kinda odd that whenever your tail lights are illuminated your speedo works. Must be a common wire somewhere in the mix. Does it sound like a ground to you though? To me it would seem like some sort of power feed wire that's common. Since whenever you feed power to the tails, whether it be from pressing the brakes to illuminate or turning them on completely, your speedo kicks on. I know I'm not being much help, but hey sometimes reading it will pop something into someone's mind. I would however assume that whatever kind of wire it is has to be either in the dash or cluster..... since the tails aren't tied into the harness that the VSS is in the engine bay. Maybe somewhere by the c500? I'm having an issue with my speedo as well, but mine is constantly over the 120 mark and never works. I'll be watch I g to see what fixes your problem. Doubtful, but hopefully something I've said can spark a thought with someone.