engine temperature gage erratic. What to do?

[shreyashp]

Hi,
I have a dodge 1991 spirit and the engine temperature gage works erraticly. I checked the connection near the radiator-engine hoze and below the radiator..looks fine..how do I check at the temerature gage's end? Am I doiing the right thing?

Thanks
Shreyas

[theFREAKnasty82]

what engine do you have?

[shreyashp]

Originally Posted by theFREAKnasty82

what engine do you have?

I have the v6 engine. The gage has stopped showing the temperature totally now...
The car has no problems...I have been using the car and have been driving everyday for about 25 miles (to work and back). The weather is about 3Deg Celsius and the fan doesnt come on unless I drive for 40mins or more continuously..

The temperature gage initially points to cold. When I insert the ignition key and turn it, just before starting, all the warning lights come on in the instrument panel and go off except the "check gages" light which remains lit. Then immediately the temperature gage needle moves from cold further back (to the lowest possible reading). Then I start the car, and the needle remails further down from cold, and remails at the same place throught...(even if I drive for 40 mins or more)

I opened the temperature sensor plug behind the distributor and tried the short the wires (to see if the gage moves) but doesnt.

I dont know if the gage is bad, temperature sensor, or something else..

Any suggestions?
Thanks

- Shreyas

[theFREAKnasty82]

over by the thermostat housing, there is a purple/yellow wire going to a sensor mounted at the thermostat housing. Nine times out of ten, that sensor goes bad, I replaced mine twice on my old '92 Spirit, V6 engine. But if you want to check to make sure get a voltmeter, hook your red lead to the end of the wire and the black lead to a good engine ground. If you have 12 volts, the sensor is bad. If you have nothing, then you have an open circuit and could be either problem in the wiring or the actual gauge itself will be bad. But if the gauge itself was bad, the whole entire cluster wouldn't work.

[shreyashp]

Great !
Maintaining this car is quite fun with the right advice ! Thanks

I realized I was checking the wrong wires...

I now checked the yellow/purple wire this time and the voltmeter read 12 volts !!! .

But I also tried one more thing...As most temperature sensors are heat sensitive resistors or thermisters, I thought if I shorted the yellow purple wire (with a resistance) to ground, the gage reading might show up..Well, nothing happend...Looks like the temperature gauge may be more complicated than what I thought..

So I think I will go ahead and replace the sensor and see..I checked at autozone..its about 23$ ..quite expensive for a temperature sensor dont you think?

Thanks a lot...

Shreyas

Shreyas

[theFREAKnasty82]

$23 is more than what I payed when I had my old '92 Spirit; I only paid $5.99. Make sure it's not the coolant temperature sensor, it's the temperature gauge, two different sensors.

[AWP9521]

There are 2 sensors, one is for the Computer to monitor and the other is for the Gauge, I looked up Autozone and they list one for $8.99, Advance Auto/Parts America lists one for $8.79 for the sender for a guage. Advance shows a sender with a single wire connection for that car but that might be a generic pic.

[shreyashp]

I really appretiate all your help. Just want to check if its the right part - it says "temperature switch" and not temperature sensor at autozone.com. Part num TU91 is about 12$. Unfortunately there isnt any advance auto parts store in the city where I live.

Thanks
Shreyas

[shreyashp]

Yeah ! Found an AutoZone about 7 blocks away !! Yeah, they have the TU91 part.

I actually went to a goodyear mechanic yesterday and he told me that the temperature sensor was bad and pointed to the incorrect temperature sensor. Here is an image where I found the correct temperature sender/sensor on the car..I hope its the right one.

http://photos.yahoo.com/shreyashp/

You guys are quite amazing..the mechanic looked in the manual and verified he was right...but after I searched other sites on the net, I found out you guys were right!!

Thanks, theFREAKnasty82 and AWP9521
Shreyas

[shreyashp]

Originally Posted by shreyashp

Yeah ! Found an AutoZone about 7 blocks away !! Yeah, they have the TU91 part.

I actually went to a goodyear mechanic yesterday and he told me that the temperature sensor was bad and pointed to the incorrect temperature sensor. Here is an image where I found the correct temperature sender/sensor on the car..I hope its the right one.

http://photos.yahoo.com/shreyashp/

You guys are quite amazing..the mechanic looked in the manual and verified he was right...but after I searched other sites on the net, I found out you guys were right!!

Thanks, theFREAKnasty82 and AWP9521
Shreyas

Hi,

I replaced the temperature switch/sensor. Doesnt seem to work !! ?? The same thing happens...The gage is initially down at cold, and when I turn on the ignition, the gage moves further down and stops. The "check gages" light remains lit.

I am sure about the 12 volts between the yellow/purple wire and ground.

Any suggestions?

Shreyas

[shreyashp]

Originally Posted by shreyashp

Hi,

I replaced the temperature switch/sensor. Doesnt seem to work !! ?? The same thing happens...The gage is initially down at cold, and when I turn on the ignition, the gage moves further down and stops. The "check gages" light remains lit.

I am sure about the 12 volts between the yellow/purple wire and ground.

Any suggestions?

Shreyas

All I needed to do was drive the car !!! I assumed that the gage doesnt work because the "check gages" light remains lit. When I drove for about 10 mins, I suddenly noticed my temp gage was working !!!!

Thanks a lot guys.
Thanks automotoveformus.com


Shreyas