2nd Gen Non-Engine/Transmission Engine temp gauge not working

[ESwartzer]

On my way to Wal Mart this morning my truck was running beautifully, when I left the store and started her up my check engine light came on and my oil pressure, engine temperature and alternator gauge wouldn't work. I came home and logged onto the TDR and discovered how to check gauges by pushing the trip meter while turning the ignition on, so I did that and my alternator and oil pressure gauge started to work again. My engine temp gauge still will not work and I show no codes with my scan tool. I have 4. 93 volts at the temp sender but I dont know how to test the sender itself. I would appreciate some info on how to do that and where else to look for the problem if if it tests out OK. Maybe my truck just doesn't like Wal Mart!

Thanks guys

 

[Missouri Mule]

From 96 Factory Service Manual for 12 valves.

Temp sensor /sending unit is thermistor that changes the electric resistance with changes in engine coolant tempature. Low resistance =high temp readings, High resitance = low temp readings.



Tempature gauge calibration

Low normal (+/-3) 155 ohms

High normal (+/-3) 80. 9ohms

 

[ESwartzer]

Thanks for the specs Bill, I appreciate your help!

 

[rrl989]

Since you experienced multiple failures at once, I would not suspect the fault to be a single sender?. I'd look at the electrical connectors, engine compartment, under dash, etc. Have you done any work on the truck lately, anything unusual happen the day the problem surfaced ?

 

[ESwartzer]

I haven't touched anything for at least 6 weeks so I don't know what set it off, however after cleaning the contacts on the temp sender the gauge started working again. They didn't look dirty or corroded at all but they must have been the problem. Thanks again for the help.

Earl

 

[Missouri Mule]

That's how my backup light switch is. Stops working take it off and spray the connectors down and it starts working again. Male and female terminals look clean.