2010 S80 T6 Fan Module Mystery

[robanarchy117]

Good Day All,

Quick background on myself. I am a long time shade tree mechanic, and certified heavy diesel mechanic. Most of my background is American made cars/trucks. I don't have VIDA, or any other diagnostic tool other than generic OBD II. I purchased a 2010 S80 T6 about two years ago with 150k miles on it. The car was a one owner vehicle that hade been maintained and traded back in at the dealer it was purchased from. Shortly after purchasing the car I drove it about 80 miles from home to training center for work. Parked the car in morning went into class, at lunch time I tried to grab lunch. The keyless entry wouldn't unlock the car (dead battery) .. I jump started the car, the cooling fan was running immediately. went to lunch came back to class. the fan stayed on again. So i disconnected the main feed to fans. I researched the boards and found, my answer. The control module went bad. Replaced the module life was good for about a year. I would occasionally get a message saying "engine hot shut car off" if I was in traffic with A/C on. I would shut A/C off and once car got moving again it would cool off, with out " over heating". This past early spring, the car had no heat. Replaced thermostat, problem solved. As seasons changed, and temps started to climb, I noticed the air conditioning wasn't working. The A/C was never really all that cold considering it being a "luxury sedan". Again, I consulted the boards looking for answers. I chased all possible answers, with no solid results. With no other option, I resorted to a local trust worthy mechanic that primarily works on European Auto's ( a long time friend of my brother). I sent the car in to be diagnosed for A/C, an oil change, And over all check to see if I had missed anything. DIAGNOSIS $300.00 reduced to $150 if repair was made. Oil change $150, A/C compressor failed completely $1000.00, Cooling fan module failed low speed only $1000. So they changed oil, and replaced A/C compressor with system cleaning and system recharge. Bruno (shop owner) said replace module your self, and life should be good. I picked the car up and replaced module in parking lot. Turned A/C on, high speed fans kicked on, and SHAZAM!!!! Ice cold air!!! wooo Whooo! Life was fantastic........ for 24 hours... The next day was miserably hot, 100 degrees with 100% humidity. I was driving car home loving life in my ice cold car after 10 hours working in grueling heat. Suddenly reality hit like a run away freight train, (engine hot shut motor of) WHAT THE $#@^%&&*%@^$#&@%#^&#@@%^&%$#@$%^^%#@#......... I pull over, no fan noise.... pop the hood (bonnet) the fans are stopped completely!!!! I reach in to unplug Fan module, the module was so hot it burnt my hand. I own a hobby farm, and work manual labor for a living. So my hands are closer to 100 year old saddle leather than they are to skin. I shut the hood, jump in the car and kill my beloved A/C. As I do this it starts to down pour, THANK GOD!!!! I start driving the message goes away and I get home. I put the old module back in and low speed fans work. I disconnect the old module and reconnect the new module nothing, new module failed. This got me thinking. Fans as far as I know are original to car. Replacement module failed and excessively hot, I figured fans are failing causing massive resistance. Hence immediate module failure. So I purchase a replacement fans and install to the car. Start car cold, no fans. Turn A/C on, fans go to high speed. Everything is working great. I let the car run in 95 degree heat A/C on for an hour, no high temp, ice cold air, life is good. I shut car off, fans keep running. I figured they would time out after idling for an hour. I go inside eat lunch, and a couple other tasks. Two hours later i go back out and fans are still running..... I open hood, small fa lower left side facing car is still running. I pull main feed wire to module and check for power, feed is good. i check for pulse width signal no current. plug it back into fan and small fan turns on again. Hmmmm, brand new module that came with fans failed. Ok, luckily I ordered another module before hand. I take the failed module out, and install new module. Start car, turn A/C on fans turn on. Shut A/C off, fans stop. repeated 5 times works as it should. So now I sit in my car with A/C on for half hour thinking I am finally victorious. I decide, ok time to get something else done and shut the car off. Fans keep running, I assume AGAIN they will time out. I come back an hour later, FANS STILL ON. What am I missing? what could possibly cause so many modules to fail? or is it possibly that I purchased the cheap 30 dollar modules from amazon? I am pretty illiterate when it comes to volvo's though I have knowledge of diagnostics, and repair. PLEASE PLEASE someone help me! Thanks in advance!