My water temperature gauge has not been working since I got the truck. I picked up a camper and ended up blowing the radiator because the gauge did not work. I've replaced the engine coolant temperature sending unit right behind the alternator. Didn't do anything. It's dark now, but just a question because when I put it in, I was in a hurry. The harness can plug on both ways. If it's not on the right way, will the gauge still work? Or not? Shouldn't this fix the problem? We fiddled with the old sending unit, and the gauge flipped around for a second, so we thought it needed a new unit. I don't know what else it could be.

 

i think the harness should fit one way... IRC.. mine only fit one way..with a lock mech. on the one side.. mine went bad one day and threw a code...replaced the send unit on the intake plenum (where your talking about) and wam bam fixed. and it should only fit one way.. b/c it measured in ohms .. when the coolant gets hotter or colder... the wires will send a different amount of current back to the gauge.. so yea..it should only fit one way... or youll get instead of 180 or 200 deg temp .. itd be more like 300 something.. exact opposite of what it should be..i think..dont quote me... an easy test to see if the old one worked good or not.. get a pot of water and put it on the stove and start to boil it... before its boiling... meter out the two prongs with a multi meter set to ohms.. around 20ohms setting.. and them check it again after the water is boiling or considerablly hotter than before..if the reading is much different then your original senor was working properly and you should troubleshoot a different area... trace back the harnes wires as far as you can go.. they may have rubbed on the block or somewhere and could have gotten shorted out..causing that..or your dash gauge might be bad .. but i havnt heard too many gauge clusters going bad on these rams...unless tamperd with previously.. worht a shot... oh..becarefull!! bioling water is hot and it hlps to have 2 people..one to hold the sensor in the water with a pair of long needle noses and the other to meter out the sensor.. when i did it..the wife held the sensor and i used a set of small aligator clip leads and shot out the sensor... good lukc .. hope this helps!!!

 

Depending on what year truck you have you may have replaced the wrong sensor. On my 97 I have 2 sensor 1 for the gauge in the truck and one for the pcm. The one for the pcm has 2 prongs and the one for the gauge only has 1 prong. In 98 they changed this and only have one sensor.

Also if you look at the sensor there is a notch on the sensor for the clip on the harness so you know which way it goes.

 

I've replaced the air temperature sending unit at the top of the intake. I've also replaced the engine coolant temperature sending unit down behind the alternator. About the other unit with one prong, where is it located? I see the wire for it. It's not hooked up to anything and is laying on the passenger side valve cover. Where is the sensor? The first sensor I bought was the one with one prong so I know it fits. The only problem is, I don't know where the sensor goes. Can anyone help me out?

 

The other sensor is located just the right of the thermostat housing. A real beacg to get at but can be done. Good luck.

 

I am having problems with these same sensores. i have a 95 ram 1500. I replaced the one that has one prong and now im gettin a temperature reading that is almost at the redline on my gauge. I have the other sensor with the two prongs what would that do if i pelaced it.

 

On my '96, 5.9 the gage temp sensor has one pin and is located behind the alternator. Located a few inches aft (on the intake manifold) is a manifold air intake temp sensor which has two pins.

I removed the connector from the gage temp sensor and substituted different resistance values to check my gage.
gage ohms
130 985
140485
170200
220 145
240 85
260 65

 

i have put two of those in and it still is reading way to high. i bought the second one because i thought the first one was bad. could it be the wrong sensore it looks the same but could it be for a different year or model?

 

Do you know what the actual temperature is?
Many repair shops have one of these. http://www.redhillsupply.com/portabl...otive-uses.htm

 

Were are you geting the sensors at? Being a mechanic and dealing with the local parts houses i will NEVER EVER buy water pumps, fuel pumps, thermostats, electrical parts (sensors, coils, injectors) from O'Riellies. I would try to get the parts at a differ place and see if you have the same problum.
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