i have the green resistor off my old fuel gauge and according to the instruction's, i am supposed to install it vertically on my temp gauge. my question is.... why does my temp gauge climb past 250 when i turn the key to the on position? i have disconnected the switched green wire that goes to the fuse block and ties to the green sending unit wire.....please help, it's driving me crazy!

The green wire that connects to the sending unit goes to the gauge, not to the fuse block.

on my car the green wire from the sending unit goes through the fuse block and inside the fuse block it goes to 2 green wires in the dash harness, 1 to the cluster (printed circut board) and the other to the ign. switch. this was a SS idiot light dash (wire going to the ign. was to let you know the temp light was working). going to gauges.

Shouldn't need that "lamp test" wire anymore.
What does the gauge do if you disconnect the green wire from the sending unit itself"
You did change the sending unit from the idiot light type to a gauge type, right?

got the gauge conversion kit that was supposed to come with the the correct sending unit. disconnected the "lamp test" wire and gauge does good until i hook it up to the sending unit and then it pegs past hot (250).

Thanks

got the gauge conversion kit that was supposed to come with the the correct sending unit. disconnected the "lamp test" wire and gauge does good until i hook it up to the sending unit and then it pegs past hot (250).

Thanks

Gauge go below 100 with the wire to sending disconnected. Test the sending unit with a ohm meter, from the terminal to ground (with the wire disconnected) I don't have the figs off the top of my head (they have been posted here in this forum before) but I believe it was something like 300 ohms cold, as the sender warmed up, resistance drops, making the temp gauge move. If you get a low resistance reading, the problem may be with the sender, if it is high, then it could be the gauge, or resistor in gauge. gauge senders work on variable resistance with temp, idiot light senders are just basicly a switch, the circuit stays open till the car overheats.