78 280SE Blower motor

[skot2]

HELP!

Blower motor on a/c heat not working. Checked fuses..........okay. Has anyone ever changed one of these out...........could it be the controls. It is the auto push button with temp dial. ANY info would be helpful.

Thanks,
Scott
78 280SE/CE

[ctaylor738]

Does it work on DEF? That setting bypasses the servo and all the temperature controls.

[Aaron]

If it works on DEFROST mode, as Chuck Taylor said, that does bypass the other functions. That also means that you most likely have a vaccum problem somewhere in the system. If the system works on the "DEF" setting only, I would start by checking the vacuum supply line on the driver's side at the firewall under the hood, also check the lines at the servo (passenger side, lots of vac connections attached), also, if you feel daring you can pull the ACC panel out and check that the big vacuum plug is secured to the back of the pushbutton unit. Let us know and good luck!

[skot2]

It does not work on defrost. I am now assuming it is the blower motor or the bushings. I have a great mechanic...........I just like to know what I am up against when I take it in for service. Thanks!

Originally Posted by ctaylor738

Does it work on DEF? That setting bypasses the servo and all the temperature controls.

[skot2]

Thanks! It does not work on defrost. I am assuming it is the blower motor that is out.......what is your experience with this component?? Thanks for the info. Scott

Originally Posted by Aaron

If it works on DEFROST mode, as Chuck Taylor said, that does bypass the other functions. That also means that you most likely have a vaccum problem somewhere in the system. If the system works on the "DEF" setting only, I would start by checking the vacuum supply line on the driver's side at the firewall under the hood, also check the lines at the servo (passenger side, lots of vac connections attached), also, if you feel daring you can pull the ACC panel out and check that the big vacuum plug is secured to the back of the pushbutton unit. Let us know and good luck!