91.5 D250,

keep blowing the blower fan, window motor, fuse, new blower fan motor already on it with new connectors, all the fusable links are eliminated with new style fuses. Could it be my fan speed switch, or could my ac compressor have an issue. It only does it when the truck is on defrost, and high speed, but its intermittent as hell.

Kasey

 

I would check the switch wiring or the switch itself

 

the wiring in these trucks is ca-ca. only the paint jobs was of lower quality. shame on Chrysler engineers for thinking that their design would be reliable

at some point the whole mess needs to be rationalized (i.e. REPLACED)

(don't ask me how I know )

 

I know in my old 78 the heater wireing sucked and my fuse block was a melted blob of gooo. I had to wire in individual fuses into the block.

Kasey

 

My long term goal on my 91 is to re-wire the whole rig, and do a custom dash with probably Isspro gauges and a spot for a bunch ( I mean a BUNCH) of toggle switches to run everything, and building a flat shelf on the drivers side inner-fender to hold all the fuse boxes and relays that I can dream up for electrical stuff!


As for the problem at hand, I'd check the switch unit and the pigtail harness right on the HVAC control unit.

 

Did you check for any trash blocking the air flow in the heater box? Trash getting stuck in there is a common problem which could make the blower act more like a compressor.

 

i kept blowing my window motor fuse when the motor was starting to go i replaced the motors and the regulators ($120) at the local oreilly and that took care of my problem

 

the fuse in the fuse boxes dont blow, its the 50amp fuse I wired in at the engine bay in place of the fusable link, how heavy amp wise are the fuseable links suposed to be? I have a new fan motor, new window motor, and the wireing looks fine nothing melted. The book shows 20 guage fusable link.

Kasey

 

I just replaced the fan switch, so well see. Im also thinkin the heater control could be it it feels a little funny, really loose.

Kasey

 

check the sticky for a wiring upgrade for the fan high speed, youll get 2-3 times the cfm, with larger wire through a relay, at the same time reducing load on the original wiring, which is too small of gauge, too much loss of voltage, its a very worthy job when done.

 

What is the "sticky" and does someone have a link to this for me?

Kasey

 

Its at the top of the 1stgen page. https://www.dieseltruckresource.com/...t-t102027.html

 

I found it, thanks guys. Ill be doing this here shortly.

Kasey