Hi All,

My 97 T-100 with 130,000 miles just lost it's heater fan. It worked great all weekend and then I went out to start up at 5:00 this morning and the fan switch does nothing. Makes my morning drive a bit on the chilly side. I checked the circuit breakers on the left side of the engine... All look good. Only thing I can think of is I wiped down the dash with some Armor All last week... could this of shorted out the contacts or do you think the fan motor just quit.

Thanks,

Vern

check your fan for corosion where i plugs in under the glove box...

Isn't there also a fuse in the kickpanel at the drivers feet?

If it's like the older Yotas, the heater fuse is in the same block as the AC fuse--behind the glovebox against the center pedestal.

Check to make sure the fan housing is grounded as the power feed is a single wire to the unit. Then check by just hot wiring the fan to see if it runs at all...If not the next is the connections and the resistors that control the speeds. Somewhere along the line you have a bad connection. Fans almost never go bad whithout making all kinds of nasty noises ahead of time.

Blower motor has full power when the switch is set to HI.

There is a heater fan relay. The coil of the relay is fed by the 10A GAUGE fuse. It's energized when the blower switch is set to anything but OFF.

The switch part of the relay is between the 100A ALT fuse and the 40A HEATER fuse. So, you should see voltage on one side of the HEATER fuse when the blower switch is on. If the ALT fuse was melted, your day would have been much worse..

Also the blower motor should have two wires on the 97 truck (there are wire colors marked on both legs).. one leg comes thru the HEATER fuse, and the other leg gets ground from the heater switch (on HI) or the blower resistors (on other speeds.)

The heater relay also supplies power to the A/C fuse (and A/C brain.) If your blower switch is on, the A/C LED should light up when you push the button in.

Thanks for all the input.

Strange thing... I started the car later in the day and the blower worked fine. I'm not sure what caused it, but hopefully it will keep going.

Thanks again,

Vern

It could be yer fan switch then... <img src="/forums/images/graemlins/wink.gif" alt="" />

I'd check all yer wiring connections before you git stuck again without any blower... <img src="/forums/images/graemlins/smile.gif" alt="" />

Switch or ground or both then....