I have a problem with my speedometer where it bounces around and just goes dead. For the first couple of minutes it works perfect, but when the car heats up it starts bouncing between speeds and finally zeros out. What could be wrong? I changed the speedo gear and I've got a speedcal.
Thats really weird. I have never used a speed cal but maybe if you have it mounted somewhere where its getting too hot it could get goofy and overheat. Otherwise try checking the wiring down there. Did this just start happening after you got the speed cal or has this just started recently and you have had the speed cal on the car for a while? Consider checking all your grounds, I know bad grounds can cause all kinds of weird stuff to happen.
sounds like the speedcal could be causing you the problem. You should consider pulling it and re wiring it, making sure you are on a good ground. Next, check you VSS over. how did you connect your wires? Then, look at the Green and yellow wires. If you have those two mixed up, the speedometer shouldnt work. im not sure if itll do what you are dealing with or if it just wont work period. hope this helps a tad.
It definitely seems like it's a heat problem, but I mounted it where you are supposed to. It works for the first 10 minutes perfectly and then starts bouncing and eventually falls to zero.