Ok boy's and girl's, I need your help. Blower for the heater does not come on in the 1,2 or 3 position, only #4. I checked the fuse and its fine. Put a new one just to make sure. As there is a fuse just for 1,2 & 3 and another fuse just for four is there a part that can burn out that just controls the firsts three speeds? Where is it, how do I replace it?

 

There is a 25 amp fuse for the three low speeds and a second fuse for speed 4. There is a relay that sits behind the glove box that switches the blower from the three low speeds to speed 4.

If your lucky the fuse for the low speeds is blown, if you're not so lucky than the resister bank is damaged (I'm not real sure where the resistor bank is).

 

Yep, it is either a fuse, or the resistor pack. I believe the resistor pack is on the blower motor housing itself.