Lately I've noticed my fan works really good sometimes and then other times it just doesn't feel like giving 100%.  Sometimes I can feel the air on my face sitting back in my seat and other times I have to be right next to the steering wheel to feel it.  It usually changes after the truck has been stopped and then re-started.  I've never noticed it to change while driving.  Is there anything I can check or am I too assume the fan will be exiting stage left eventually? 

Time to change both blower resistor and the blower motor. The blower motor bearings start to fail and draw more amps across the resistor which now the resistor is randomly work or not. This is why you need to replace both.

What about the switch?  Today I was checking the various speeds on the switch and when I got to low, the fan stopped and I couldn't get it going again.  It started back up on it's own about a minute later.  Could that still be the resistor?

 

I am getting ready to sell my flatbed, planned to use some of the proceeds for a new dash core, top, bezel, and heater core/fan.  I guess I will add the resistor to the list.  Hopefully it can hold out another month. 

 

EDIT:  I just realized those 2 parts can be replaced without dash removal, lol.  I guess I'll grab them in a day or two.  Still, do you think the switch could have anything to do with it or is it most likely just the other 2 things?

Edited August 2, 20187 yr by Sycostang67

Still got to replace both the blower be cause the bearings are bad. Then the resistor is failing for sure it will be all broken on the ceramic. As the resistor cools the fan starts again. 

Got a new fan and resistor switch installed today and everything is working great right now.  I went through all the switch settings and it never shut off like before.  The old motor was fairly difficult to spin, I'm surprised I got any strong air from it at all.  All the exposed metal on the old resistor was nice and green as well.  Now I shouldn't fry in the 100+ temps we'll be getting this week. 

Strange but true, like I said as the bearings give up the current flow starts to heat up the resistor. When the resistor fails you can bet the blower is just as damaged. So would you be will to post a pic of the resistor?

Edited August 6, 20187 yr by Mopar1973Man

Sure, no problem.  I imagine this is original as I think the fan was as well, 17 years and 226k miles.

 

Edited August 6, 20187 yr by Sycostang67

Wow. The ceramic didn't crack. The legs are oxidized. I'm betting the problem is in the core of the ceramic which is a wire wound resistor. 

Yeah, just had a sliver or 2 of ceramic come off while I was removing it.  The box was pretty clean too, only had one pine needle in the cage. 

Did you look at the evaporator with a mirror and see how much junk is collected?

 

Thanks for the thread, I've had minor issues with mine, ordered new blower and resistor from Rock Auto 

I replaced the motor and got to do the resistor. Is the resistor a PITA to replace? My hands are probably too big.

 

L8tr

D

Neither are hard. Resistor is 2 screws and it drops out the bottom on the passenger side foot well.

22 hours ago, Mopar1973Man said:

Neither are hard. Resistor is 2 screws and it drops out the bottom on the passenger side foot well.

I didn't think to check with a mirror, but where I live, that kind of nature isn't around to get into my system.  I'll definitely check when I do the entire dash though.

 

Swapping the parts was really easy, took me about an hour but that involved swapping the cage and plug and cleaning the built up dirt off the cage as well.  Having that fan going full blast was really appreciated during my camping trip when outside temps were over 100*.  Before the truck would get cool but I would still sweat pretty good.  Now I actually have to turn the A/C down after a bit. 

I'm about to do mine too, parts arrived from Rockauto 

FYI, my resistor was junk and blower was trying to turn on low speed but couldn't, bearing/bushing was dry and therefore I'm guessing it fryed the resistor. So I put new motor and resistor in, but after few drops of oil in old blower it freed up and was also working on low speed. So I kept it as a spear.