[Snowman]

93 Seville 4.9L

A few days ago the HVAC blower motor started going to low speed, then back to high erratically in every mode. I checked the DC at the motor connection at the firewall, and the DC is going down then back up again while the fan is set th HI in ECON. The same fault persists in AUTO & DEF.
The fan motor seems fine, is running quiet isn't running hot . Any ideas ?
I don't have a shop manual or wiring diagram for the car .

 

[91TexasSeville]

93 Seville 4.9L

A few days ago the HVAC blower motor started going to low speed, then back to high erratically in every mode. I checked the DC at the motor connection at the firewall, and the DC is going down then back up again while the fan is set th HI in ECON. The same fault persists in AUTO & DEF.
The fan motor seems fine, is running quiet isn't running hot . Any ideas ?
I don't have a shop manual or wiring diagram for the car .

There should be a fan control module mounted at the top, about mid way on the plenum, against the firewall on the engine side. That is most likely the culprit. Sooner or later your fan will stay off or on (and never shut off) when the unit fails completely.

I have written about this before and provided the wire schematic for all connections. It is an easy R&R when the time comes.

 

[Snowman]

There should be a fan control module mounted at the top, about mid way on the plenum, against the firewall on the engine side. That is most likely the culprit. Sooner or later your fan will stay off or on (and never shut off) when the unit fails completely.

I have written about this before and provided the wire schematic for all connections. It is an easy R&R when the time comes.

Thanks for the info, found the BCM, I'll order a new one tomorrow, hopefully the part is still available from the General. Today is a holiday here and everything is closed.
Thanks again.