Check Engine light GONE! Fans STILL run all of the time

[davew833]

Today, in my ongoing quest to figure out why both my cooling fans run all of the time, I bought a brand new temp sensor (the one with the two-pin connector) which I installed, and then attempted to clear/check the ECU codes. After connecting the blue wire(s) in the proper way and turning the key, I got NOTHING, no 'check engine' light at all.

Further investigation showed the 'check engine' light didn't EVER come on at when I turned the key. I figured the bulb must be bad. Upon closer examination, I noticed half the screws were missing out of the instrument cluster trim panel. I removed the rest of the screws, and removed the instrument cluster itself to find that the 'check engine' light was GONE! The bulb, the housing, the whole thing!

Knowing that my car passed through the hands of four or five used car dealers before it ended up at the auction where I bought it (with a bad front diff), the missing bulb is a good example of what some unscrupulous used car dealers and/or repair shops will do to pass off a car as being in top running condition. (For all I know, the odometer was rolled back too when they had the instrument cluster out!) The moral of the story is CAVEAT EMPTOR, or specifically, ALWAYS make sure the 'check engine' light comes on (and goes off) when you start that car up you're looking to buy.

The good(?) news is that I replaced the 'check engine' light assembly, checked/cleared the codes, and the light blinked regularly to indicate there were no error codes, BUT MY FANS STILL RUN ALL OF THE TIME! (sigh...) Does anyone know WHICH TEMP SENSOR activates the cooling fans? Maybe it's the other one that's bad. (The dash temp gauge works, though.)