Temperature gauge isn't working

[silverF250]

Okay another question. I did a water pump on my truck and in the process of switching the temp sensor over I dropped it and it broke. I got a new one from Napa got everything back together and know I don't have a working temperature gauge. I'm on my second temp sensor and still don't have the gauge working. Does any one have a clue as to what could be going on? I've checked the fuses and didn't find any bad ones. The only thing I can think of is get a sensor from the Dealer.

 

[DaveBen]

Check the wires to the gauge unit. One of them may be broken. Sensors don't usually go bad out of the box.

 

[JMF350]

Ground the sensor wire to check the gauge.... may not be sensor.

 

[silverF250]

Best way to ground the sensor wire? I'm a carpenter not an electrician.

 

[DaveBen]

I am a carpenter too. But you can ground the sensor wire, next to the sensor, by touching it to the bare metal part of the engine. Then look at your gauge and it should read as cold as the gauge gets.

Dave

 

[RandyH]

I recalled seeing a similar post on powerstrokenation.com and as it turned out there was a problem with multiple replacement sensors. Kinda of odd to have more than one bad replacement but could happen especially if they're coming from low-cost countries.

Temp sensors typically are either open or shorted when they go bad. Occasionally you see one that changes value but that shouldn't be the case with yours or you would still see it register, just incorrectly. If you're familiar with using a multimeter you can put the probes across the sensor terminals (if 2 terminals) or from a single terminal to the metal sensor body. If open, you should see infinite resistance, if shorted you will see close to zero ohms resistance. Not that familiar with this specific sensor so not sure what they look like. You should be able to call the parts store or Ford and ask them what a good sensor reads at ambient temperature.

Here's that other post I found:
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southmike
Online
Village Idiot Join Date: Jul 2007
Posts: 1,601

Re: Does a bad Coolant temp sensor affect performance

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I broke my coolant sensor ..didn't affect anything other then a useless guage driving me crazy...I tried three different sensors from autozone or advance none worked. foolishly I assumed they were cheaper. then I gave up bought it from the dealer , it worked and was cheaper go figure .
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early 99 f350 4x4 crew cab, auto.
Diy Twin tymar, TS chip, Powerslot rotors & Hawk pads, ford AIC, pmt2 pcm ..... with big fat want to list.
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[silverF250]

I am a carpenter too. But you can ground the sensor wire, next to the sensor, by touching it to the bare metal part of the engine. Then look at your gauge and it should read as cold as the gauge gets.

Dave

It already is as cold as it gets. I'm going to try and get one from the dealer and see if that helps.

 

[KRISTOLSON]

here is a thought, when you put in the sensor, did you use teflon tape? that may be insulating the threads from making contact and completing the circuit...

 

[silverF250]

Nope liquid teflon.

 

[KRISTOLSON]

either way, any thread sealer could be doing the same thing. Take a multimeter and measure resistance between the body of the sensor right above the threads and the casting it threads into. it should read little to no resistance. also, when I bought an oil pressure sending unit from napa, it was listed as the corect part, but the voltage range it produced was way off, and would not work. maybe they are giving you the wrong sensor? the ford one might be a good idea if all else fails