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Temp guage not reading right


kimcrwbr1

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The 1 wire is the sending unit to the guage pull it off and touch it to ground with the key on it should read all the way hot. the one with two wires is for the computer to tell it how to control the fuel mix cold vs hot and other things. If you have a volt ohm meter you can check the wire to the sender 1 wire it should have around 8 volts that pulses. All the guages run on the same power supply if you check the wire to the oil pressure sender it should have the same voltage as the water temp sender if not the guage may be bad like i was saying the connector for the water temp somtimes gets loose or corroded giving you an intermittent signal to the guage. just take a pair of pliers and crimp it a little so it pushes on tight and see if that does it.
 


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Tested the one wire with the paperclip method, it went right up to the H like you guys said it would. Now for the thermometer test in the coolant with the rad cap off.
 

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OOOK, sooo no flow with the coolant with rad cap off as far as I could tell, it didn't overflow the radiator, coolant level normal. Coolant temp on the top hose was at most 145 degrees, but it felt pretty darn hot. The bottom hose was much cooler, I didn't measure temp on that, cuz it was nowhere near as hot as the top one is. Checked the temp of the coolant with rad cap off, no more than 130 degrees.
 
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doorgunner said:
there's an ohm test for the sensor.....with the engine cold, the sensor should read a certain amount. After the engine is started the ohm rreading should change noticeably as the engine warms up .... maybe I saw the test in the Tech Library...grounding the dassh gauge should cause the gauge to max out hot if it's working correctly.(that will eliminate having to take the dash apart)



I couldn't find any specifics on readings for these sensors...dunno if I wasn't looking in the right place or what.
Click to expand...
 
doorgunner

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machgirl said:
doorgunner said:
there's an ohm test for the sensor.....with the engine cold, the sensor should read a certain amount. After the engine is started the ohm rreading should change noticeably as the engine warms up .... maybe I saw the test in the Tech Library...grounding the dassh gauge should cause the gauge to max out hot if it's working correctly.(that will eliminate having to take the dash apart)



I couldn't find any specifics on readings for these sensors...dunno if I wasn't looking in the right place or what.
Click to expand...

Engine is hot....... 3 ohms

Engine is cold........ 40 ohms
Click to expand...
 

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Thank you!!
 

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Turns out it was the temp sender, the one-wired sensor. I feel stupid now lol. Thanks guys for all the tech help.
 
kimcrwbr1

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Yea I took my ranger for a spin yesterday after sitting for two months, and noticed the temp was still on cold. After freakin out checking everything else first it was the connector for the sender loose. I flashed on this thread and just had to laugh why I didn`t check that first. I`m glad it was something simple and cheap. Was one of those part numbers the one you used.
 

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I went to Oreilly's and bought one. 8.49 :)
 
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