Hey guys on my 56 Chevy truck I’m having issues with the temperature gauge pegging out all the way HOT. I have a new temperature sending unit in it as well. I was told to take the Teflon tape off of the threads and screw it back into the manifold. My gauges are original but they have been all rebuilt and tested. Any suggestions. Thank you
The gauge itself can cause problems...they have a tendency to get a loose connection where the little wire from the magnet goes to the terminal. Might need to get the gauge rebuilt again, under warranty if possible. But first make sure the wire from the sender to the gauge is not loose anywhere.
If the sender wire is working ok, then it's probably the gauge. Use an ohm meter to troubleshoot it...disconnect the sender wire from the gauge, measure the resistance between the wire and ground. If it's infinte, then you have a problem with the wire or sender. If it's a reasonable number (less than 1000 ohms), then the gauge is bad.
Hey guys I’m still having issues with the temperature gauge. Today I went out and ran the truck without the radiator cap on it for about 10 minutes or so. The temperature gauge did not move at all from the Cold position. I reved the motor a few times and the needle just shot over to the HOT position and stayed there. There was no gradual temp rise just instantly cold to hot. I unhooked the wire from the temp sending unit that’s in the intake and the needle still stayed in the Hot position. Any advice? Thank you
If the gauge doesn't move when you disconnect, then reconnect the wire from the sender, then the gauge is most likely bad.
Agree, with one small caveat. I don't remember the specifics of that dash, and since this seems to be a new install, is it possible to short the wire at the gauge when installing it? I'm thinking maybe a ring terminal that is too big for the jobt touching the case when snugged up.
They use clips on a round pin to connect the gauges on these trucks. It would be pretty difficult to short that.
If I recall, the sender should be 600-700 ohms when cold, I think they get less resistance when warmed up. But do the Google thing if no one confirms it and what the numbers should actually be. So measure the resistance, wire off, from the top of the unit to a known ground on the engine.
you might also measure the resistance of the gauge itself, after disconnecting the wires from it. Measure from each terminal, to ground (the metal housing)
Correct Original 1956 Chevy Temp Sender 32º = 1110Ω 100º = 600 Ω 150º = 380 Ω 180º = 275 Ω 185º = 265 Ω 190º = 255 Ω 212º = 200 Ω AC replacement Temp Sender 1513130 for a 57 Chevy. 150º = 318Ω 160º = 278Ω 170º = 247Ω 180º = 227Ω 190º = 205Ω 212º = 155Ω
From reading post #5,,,,,I believe Squirrel is right,,,he needs to check his gauge,,,,and the attached wiring for some issue . Straight to hot from cold,,,,,sounds very strange to me . Tommy
If you read post #5 it sounds like the sender is air locked. When he reved it the temp shot up to hot.
A faulty sender will do exactly what is described. The easiest way to check the gauge vs sender is to unplug the sender and connect up a wire with a 275 Ω resistor in it [and ground it] The gauge should remain stable at approx 180º. If the gauge keeps climbing with constant resistance, then look at the gauge Resistors are about 15c each
So I drove the truck yesterday and when I parked the truck the gauge was still on HOT when I went out there today. So I turned the key on and it stayed on HOT. I started the truck and it stayed on HOT. I removed the battery cable and it still stayed on HOT. I removed the 3 screws holding the cluster in and removed the cluster from the dash. Once the cluster was out the temperature gauge went down to COLD. So with me not knowing. What would this mean? Thank you
I would check the connectors on the back, sounds like it's grounding the sending unit wire through the dash.....you removed the ground path when you took the cluster out of the dash. The barrel connectors have a plastic cover over them, they get brittle and break off sometimes. The cover protects the connector from grounding AND keeps the connector tight (won't spread out), without the cover the contact can be pushed up to the back of the gauge (grounding out the sending unit.
It has the paper on the outside, but I think it still might be grounded. One way is to unhook both wires to the gauge (with the truck key off), get your meter, put it on ohms scale, touch one lead to the sending unit pole on the gauge and the other meter lead to the screw holding the temp gauge housing to the cluster......it should be "OL". If you get any other reading (other then "OL") that means the pole is grounding.
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