Blower Fan Trouble!

Dottelito · Post by **Dottelito** » 10 Aug 2021, 07:51

The blower fan in my 855 has a problem. The fan never stops blowing, even if there is no key to the ignition. The previous owners "solution" to this issue was go just disconnect the fan and pretend the problem isn't there.

I thought that it might be the blower fan resistance that needed changing but after buying a new one and installing it it made no difference at all, still blows like a hurricane even with no key in the ignition.

Anyone know how to fix this problem?

Post by **RickHaleParker** » 10 Aug 2021, 10:59

Sounds like a short tn the harness between the ECC and blower control module ( AKA blower fan resistors ).
12V shorting to one or more of the control lines.
The 12V to the blower control module is hot at all times. The 12V to the ECC is switch with the key.

To check for shorts in the wiring harness.

1. Disconnect the battery.
2. Disconnect the ECC and blower control module.
3. Check for shorts between the Red power wire and the three other input wires to the blower control module.

Post by **BEJinFbk** » 10 Aug 2021, 14:10

Troubleshooting is easier if you can tell us
which climate control system your car has.
Manual ( MCC ) or Electronic ( ECC ).

Does your fan control have an AUTO mode
and a variable control ? ( ECC )

Or just a 4 speed switch? ( MCC ).

Dottelito · Post by **Dottelito** » 11 Aug 2021, 05:15

It is a mcc, but I found some other wires that werent connected to anything, (the previous owner really tried to hide that the car had this flaw)