Things to check for a "missing" 4th speed. A bad fan switch. A bad 4th speed relay. A problem in the wiring from the thermal trip to the relay to the fan motor. Since the fan works in 1-2-3 speeds it rules out a problem in the mode switch and the fan motor. The first thing to try is switching the 3-speed relay with the 4-speed relay. Make sure that all of the connecters are in correctly ie: none of them have backed out of position and then are not making contact with the relays. Inspect the fan circuit breaker for all of the wires to be connected in particular there should be 2 brown wires on 1 side of the breaker (1 brown wire goes to the 3-speed relay and the other brown wire to the 4-speed relay). The most likely trouble is the relay and the next most likely is a slipped connecter in the relay block. The speed switch doesn't fail very often. To rule out a wiring problem you could pull the 4-speed relay and with a paper clip jump the brown and pink/black wires to get 4th speed. If the fan then runs check the black wire for continuity to ground and power at the pink/light green when you put the sped switch in 4 speed. David Teitelbaum vin 10757 --- In dmcnews@xxxx, "Ryan Foster" <westiething@xxxx> wrote: > I know this might sound silly, but the fourth speed on my fan doesn't work. > 1. Could this be a bad switch? > 2. could this be a bad fan motor? > 3. any other ideas this could be? > > Thanks for any help! > > Ryan- vin.#16301 [moderator snip]