temp gauge help
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Joined: Aug 2005
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temp gauge help
Ever since I bought my 79 f-250 the temp gauge hasnt worked and I dotn know why from what I can see it is hooked up. (im not really electrically inclined) And I changed the thermostat I dotn know what I gotta do to fix it but I really want the factory one to work instead of just installing an aftermarket one...
Posting Legend
Joined: Sep 2001
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The old original units work well if the wiring and instrument panel connections are cleaned. The OEM units do not have "numbers" but then the aftermarket units with "numbers" are wildly inaccurate also. Many modern trucks have idiot gages which do not work at all.
The biggest problem with older gages is getting the right sending unit. Many parts stores will sell an idiot light unit when a gage unit is needed.
The biggest problem with older gages is getting the right sending unit. Many parts stores will sell an idiot light unit when a gage unit is needed.
Last edited by Torque1st; Jul 6, 2006 at 01:41 AM.
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From: Virginia
Find the sensor out at the engine block. It will have one wire going to it, and will be red/white or white red(I can't remember which, one of them is the oil pressure wire).
Take the wire off the sensor, and with the key in run, touch the wire to a clean place on the engine block. When you do this the temp gauge should be full scale hot or cold. Then take the wire off the engine block and hold it in the air. The temp gauge should swing the other way opposite from when the wire was touching the engine block. Everytime you touch the wire, it should swing back and forth.
If the above test works, then that means the wiring and the gauge are ok, and there is a problem with the sending unit.
Make sure you do not use any sealer on the threads of the sending unit. It has to make a good connection the the engine block.
Take the wire off the sensor, and with the key in run, touch the wire to a clean place on the engine block. When you do this the temp gauge should be full scale hot or cold. Then take the wire off the engine block and hold it in the air. The temp gauge should swing the other way opposite from when the wire was touching the engine block. Everytime you touch the wire, it should swing back and forth.
If the above test works, then that means the wiring and the gauge are ok, and there is a problem with the sending unit.
Make sure you do not use any sealer on the threads of the sending unit. It has to make a good connection the the engine block.
