- Mar 2, 2012
- 6
- 0
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The cooling fan on my 06 GT doesn’t work. This is a project car and it wasn’t working when I bought it. I’d rather fix it right than just rig the fan to run continuously when ignition is on.
Here's what I have checked out so far. What have I missed or should try? Many thanks!
Could the PCM itself be bad?
What have I missed?
The car had some front end damage by a previous owner, so I'm suspicious of wiring problems.
Thanks for your help!
Here's what I have checked out so far. What have I missed or should try? Many thanks!
- Direct wire from battery: HS fan works, not LS, thus LS resistor might be bad
- Fan plug is in good condition, no burned terminals.
- PCM relay is energized when in Run.
- Shorting HS relay does make the HS fan work.
- Shorting HS control relay that goes to PCM to ground makes fan run all the time ignition is on.
- LS fan won’t turn on by shorting relay—12v is at relay, so perhaps resistor is bad.
- Have not tested LS resistor yet. (though HS runs when relay is shorted)
- Swapping relays, diode, fuses with tested good—no change, all good.
- The fan fuse 40A is hot. This was blown when I got it, but replacement doesn’t blow. Odd.
- Hot at pcm diode and at each fan relay, diode is ok.
- Temp gauge works properly. Does it get the same temp info as the PCM uses to control the fans?
- Is there a 2nd temp sensor besides that under intake manifold?
- The 2 wires for the HS and LS relay control from bussed fusebox to the PCM computer have continuity. (relay sockets to pins 6 & 7 on big PCM plug)
Could the PCM itself be bad?
What have I missed?
The car had some front end damage by a previous owner, so I'm suspicious of wiring problems.
Thanks for your help!
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