Temp gauge

[dbutler]

I know this has been beat to death and I have researched ect. Here is my issue....so my temp gauge was pegged past hot.So, I put a ground wire from the side of the gauge to the cluster to make sure the gauge was grounded and disconnected then wire at the sender and the gauge when back to cold. So this told me the sender was bad even though it was new. Well I ordered a new $40 sender from lectric limited because I read everyone was have good results with these. I put the new sender in and connected wire and the gauge pegged again. However this time when I disconnected the wire the gauge moved back to hot but not cold. The battery doesn't have full juice, could this be part of the issue. At this point I don't know what else to check or do...any help is greatly appreciated.


Thanks,
David

[dmjlambert]

My top suspect is your green wire going to the sender has a short to ground somewhere along it's path. It could be on the wire where it goes across the engine, perhaps melted to a manifold, or where it goes in a wire bundle, under the dash, or on the printed circuit on the back of the instrument cluster. I suggest trying disconnecting the printed circuit from the gauge and fold it back and keep it back with some tape, and then run test wires with alligator clip directly from the sensor to the gauge and see what you get. Then if that fixes it, a short is the problem, examine the truck's wire and printed circuit closely. Note that the connecting between the wire bundle and printed circuit just pinches the thin printed circuit between the connecting pins and the metal case of the cluster, so there is a potential for something wrong there. It's a very thin sandwich with layers of cluster case, plastic printed circuit base material, foil trace, terminal pin, and plastic connector.