Temp gauge on dash not working but EVIC does?

[aaldaco78543]

Hello, I have a 2005 Chrysler 300C, using a CAI 91oct tune w/180 JetStat T-stat. I recently restored my car back to the factory stock tune and also reset my fan settings back to stock because I took my car in to the dealership for some work to be done. I noticed that when I restored my car, my dash temp gauge was not working. So I figured when I got my car back from the dealership and put my tune back on and changed the fan settings the gauge would probably work again. So I have my car back and have put the tune back on and changed the fan settings but my dash gauge is still not working. When I go the the EVIC display the temp is reading correctly at 180 +/-5 degrees.

How can I fix this? Do I need to replace the t-stat?

[Mike_Levy]

It doesn't work at all, or it doesn't read the same as the digital? I haven't had my 300 in like 6 years, so I don't remember which is which, but one is coolant temp and one is oil temp. They shouldn't read the same. If the coolant gauge isn't working then the sender could be bad. Its not the thermostat. That has no effect on the gauges functionality. Same with the oil gauge. The sender could be bad.

[aaldaco78543]

It is the engine coolant temp gauge on the dash. For a couple of weeks it has not been working at all. The reading shows below the C (cold) marker. Normally when I turn my car on and it runs for a while it gradually warms up and the reading is between the H (hot) and C (cold) symbol.

When I get into the EVIC display the Eng. Temp is reading 185 degrees F. I guess that reading comes from the oil temperature???

This is why I was thinking since my Tstat is not OEM that might be the issue???

[Mike_Levy]

Tons of people have swapped T-Stats with no problems. I doubt thats the issue. Most likely its the coolant temp sender.

[aaldaco78543]

OK. The reason I was thinking it was not the sender because it was working fine. The dash gauge worked when I had the tune on. As soon as I restored the factory tune the temp gauge stopped working. When I had the factory tune on my temp gauge never moved. When I got my car back from the dealership and put the tune back on I changed the fan settings back to 180. In the past week my temp gauge did read once. I got in my car ran a few errands and it was reading correctly. Now it's back to not working. But I am confused because my fans are coming on??? but how would they know to come on if the sender was bad and not sending the temp to the ECU/PCM not sure which one????

[Mike_Levy]

Hummmm....... maybe the cluster is bad?