06 Torrent V6 the temp gauge stopped working and the cooling fans run all the time when engine is running. I checked the relays and sensor plugs and they were fine, so I replaced the coolant temp sensor in the head and everything went back to normal, then a day later, the same symptoms returned. I replaced the replacement sensor and it started working like it was supposed to, then the next day it happened again. I am a mechanic with with professional experience going back to 1988, and before I went pro all the way back to the late 60's. I have never seen a sensor fail repeatedly like this and am in a quandry. Anyone out there had this experience. I have been on the internet looking and have had no luck. Remember I changed the original sensor with a new one, then when that one failed replaced it
If you are going back to the same source for the sensor, it could be there was a bad production run of the sensor: it could be a manufacturing defect. Try a different source for the sensor and see if it doesn't cure the problem.
I agree this is a really strange issue. I have never seen where a single sensor would fail repeatedly. IMHO, it still boils down to the sensor itself. If it were getting fried because of over voltage, it would be affecting the computer as well.
One other thing you may be able to check is to pull the plug at the senor and reattach it. If it comes back to life, it may be something which you're not seeing inside the plug which is causing it to lose connection. This is a long shot, but worth a look-see. (I know, you've probably tried this already.)