TC heater fan

[Bodie Coates]

heater fan does not switch on. fuse is good,jumped fan moter off battery ,works good. How do you test switch in dash.tried test light on 4 terminal plug on back of switch, not sure what is what other than ground.?????:confused:

[Tman70]

The year of your car would be helpful!

[98TC-Cartier]

If its like most other Tc's, the power goes to the blower motor first, all the controls are on the ground side.

[Bodie Coates]

Sorry:o 89

[joedogg]

If its like most other Tc's, the power goes to the blower motor first, all the controls are on the ground side.
That being true it would be a good idea to ground both of the pins of the connector to the body with a multimeter (Ignition turned to RUN). This will show if you're getting power. After that multimeter connect them together to see if the A/C controls change the voltage. I'll bet this will show if its on the ground side or the power side.

[nailfoot]

In my 89 the fan would only run in HIGH. The ground wire on the fan housing in the engine bay had become disconnected (The ground wire is on a spade connector and slid out from under the screw). Once I connected that wire, the fan started working in all speeds. So, if you have a loose or broken ground wire, that will disable the Auto, low, and medium speeds. I bet the high speed would also be affected by its own loose ground wire.

[Tman70]

Thanks, Bodie, and welcome to LOL! The current question is... Does it work in 'Auto' mode or just in 'High'? Next, go under the hood to the firewall and look directly underneath the heater hoses. You should find a 5 wire connector going to the blower motor resistor block. Check to see if it's melted. Disconnect it and run a jumper to ground from the black wire. See if the motor works then. You can also jumper the black wire on the back of the dash switch the same way (only don't disconnect that one).

[gadget73]

Does the blower work in positions other than 'floor' ? If so, it is likely the thermal blower lockout switch, which is located in one of the heater hoses and should be in the rear area of the valve cover on the passenger side.