I have a 2001 dodge ram diesel. The blower motor only blows on high and fades in and out at that. I have changed the resistor seemed to work for a few hours and is now back to doing the same thing as before. Not sure where to go from here. Any suggestions?

. Check and clean all electrical connections to the blower motor, after removing the negative battery cable.

. Remove and clean the blower motor fuse, which is likely located in the under hood fuse/relay box.

. Remove and clean the contacts going to the blower motor relay, likely located in the under hood fuse/relay box. Use #240 abrasive cloth or steel wool. Afterwards, coat contacts with dielectric grease. If your truck has this relay, my bet is it will solve the problem.

. Check/replace the blower control switch, if problem persists.