Have a 2009 platinum, 5.4, supercrew with dualzone heating and air. The blower motor resistor block is overheating and melting the connector block. fooled with it way too much, and then put a new resistor and pigtail in it. The new resistor would kick out in about 30 seconds, so used the old resistor on the new pigtail, got hot, melted the new pigtail. What is causing the resistor block to get so hot, and what do I do about it?

 

Is there anything else connected to that circuit - some kind of aftermarket accessory?

Welcome to FTE btw

 

The blower motor may be pulling too much current...binding up, bushings shot...or something like that...

 

^^^^ Yup. That'll do it.

 

Thanks for the replies, had a small emergency to take care of, It might be the blower motor itself, although its not very old itself, and its not making any racket. There are no other circuits aftermarket or otherwise that I know of. Had a little problem with the upper air door, but its been replaced, and every thing seemed good. was hoping y'all would know of a possible short or something. is it possible that the resistor block is shorted?

 

Something is drawing way too much juice, the blower motor is a good bet. Could chase out the blower wiring I guess.See how many amps the fan is drawing compared to spec.

 

hey tedster, sorry I missed your post, and by now I think you're right, the blower is simply drawing too many amps. I've ordered a new harness and blower motor, when it comes in I'll let you know what happens, Many thanks.

 

Well there aren't too many options, unless somebody started hanging accessories on that circuit, it almost has to be the blower motor itself. They start drawing lots of juice when they go bad.

Could "hot wire" it in series with an ammeter and battery and see what it draws. Not sure but around 5 amps might be typical. Spec should be in manual to be sure.