I have a 2006 Dodge Ram 2500 (5.9 L Cummins diesel). I’d replaced blower motor about 3 weeks ago and all was well until it started working intermittently. Resistor looked burnt and cracked so I’d also replaced it. Motor sounded like it was trying to run as if low voltage. Now nothing. Does this model year truck have a relay in the system as well as the resistor, and if so, where is it located? There are no relays in fuse box under the hood. Or is this a problem with the switch, and how test it?