Another Blower Motor Thread

[jlrohio]

And here we are again, back again after 3.5 years - Guess what!!

Blower motor is acting up - only runs during the high fan setting. Looks Like I'm heading back to Advance Auto for a warranty replacement!

 

[J_C]

At least it's something easy, and free under warranty. Think I replaced mine last in 2010... so it's about due to fail again, but looks like I got it from Autozone so probably a lifetime warranty on mine too.

 

[jlrohio]

At least it's something easy, and free under warranty. Think I replaced mine last in 2010... so it's about due to fail again, but looks like I got it from Autozone so probably a lifetime warranty on mine too.

I may have to look into this a bit more, after reading some other Blower Motor threads.
Mine is only turning the blower motor on in the highest position. Nothing with the other positions.

Maybe it's something more than the blower motor (which at this point is easy (and free) to changeout)???

 

[J_C]

My bad, I had thought you were talking about the blower motor resistor, because that is the classic symptom of the resistor module failure, to have only high speed fan and no other speeds work. The resistor module is what I replaced in 2010, am still on my original fan.

There is nothing wrong with your fan motor if it seems to be spinning at full speed on high setting. The blower motor resistor is a little down and towards the center on the firewall, IIRC. There is a slight chance that the problem is instead your fan speed switch or wiring, but it's far more common for the resistor module itself to fail. One typical thing you can test on that module, is that the resettable thermal fuse (looks like a little bullet) becomes permanently open circuit, infinite (or nearly so) resistance checking it with a multimeter.

.

 

[jlrohio]

My bad, I had thought you were talking about the blower motor resistor, because that is the classic symptom of the resistor module failure, to have only high speed fan and no other speeds work. The resistor module is what I replaced in 2010, am still on my original fan.

There is nothing wrong with your fan motor if it seems to be spinning at full speed on high setting. The blower motor resistor is a little down and towards the center on the firewall, IIRC. There is a slight chance that the problem is instead your fan speed switch or wiring, but it's far more common for the resistor module itself to fail. One typical thing you can test on that module, is that the resettable thermal fuse (looks like a little bullet) becomes permanently open circuit, infinite (or nearly so) resistance checking it with a multimeter.

.

View attachment 439325

Sorry...just getting back to this.
Just verified again, that the fan ONLY works in position 4 (or high).
Going back out right now to try and find this resistor. I'll probably be back with a picture asking to ID it... LOL

 

[jlrohio]

Sorry...just getting back to this.
Just verified again, that the fan ONLY works in position 4 (or high).
Going back out right now to try and find this resistor. I'll probably be back with a picture asking to ID it... LOL

I could not see anything on the Firewall.

Here's some pics. Could you let me know if you see it and point it out? I'll also go looking at the other threads.

It's not "below" the blower motor, is it?? Last pic.

 

[jlrohio]

I could not see anything on the Firewall.

Here's some pics. Could you let me know if you see it and point it out? I'll also go looking at the other threads.

It's not "below" the blower motor, is it?? Last pic.

View attachment 439354 View attachment 439355 View attachment 439356

Ok, for a 1999, the RESISTOR is down next to the motor, in the blower motor housing.
Here's a video from the 1A Auto guys showing it.

 

[J_C]

Yes that is where it is on my '98, not really in the housing, he just moved all those parts so the camera had line of sight to it, otherwise it was blocked by the motor sticking out.

I don't recall having to remove all the parts he did to replace mine, but I suppose it's possible and I just forgot that I did.

This is a screencap from the video:

 

[J_C]

Yeah I think I just stuck my hand down in the gap in your 3rd pic, with a stubby ratchet (maybe short socket extension too) to get it off and back on, used a pick to pry up the catch to release the tab on the connector to it, to unplug it, probably before I unbolted it. There's just two bolts, one on each side. I might've also taken the air hose off the side of the motor.

 

[jlrohio]

@J_C

Thanks for your pointers... I appreciate it.
My son (the primary driver of this Explorer) and I are going to get the part from Advance (or Autozone) this weekend and plan to do it Sunday.

I'm going to have him take out the washer fluid/radiator overflow containers and the other piece in front of the blower fan to have full access to it.

I imagine, at 24 years old, that harness is going to be a bitc4 to remove...so the extra room should help. I also want to remove the motor and clean out the bird cage, etc...it's been a few years.

 

[jlrohio]

Got in there today and switched out the Blower Motor Resistor. $15 from Autozone.

As others have had issues with disconnecting the old resistor out of the wiring harness, I too did. I didn't spend much time screwing with it, as I knew that after 24 years, and seeing the rust on the other side of the resistor that it was going to be stuck in there good...I just basically broke off the plastic of the old resistor housing with a screwdriver and needle nose pliers until it just came off (see pics). Just had to be careful not to damage the wire harness side. I wish I had dielectric grease but I don't - I placed an order on Amazon and I'll un-connect it when it arrives and squeeze some in there to help protect it for the future. I went ahead and moved the air filter box out of the way and the washer/radiator tanks forward and that cruise control thing-a-majig to gain full access and make the job easier - probably added an additional 5-10 mins but gave me plenty of room to work.

When I had the old resistor out, I pulled out my multimeter and did some continuity tests across all parts of the new and old resistor. Bascially, on the new resistor, I had continuty on every part I tested across. On the old resistor, I had continuity across most of the part, except anything that had to do with that bullet shaped resistor. There did not appear to be any breaks in the spring wires - just a lot of rust for being exposed to lots of moist air. I too also had some dust or other fabric wrapped around the base of the resistor springs.

Thanks-you @J_C for the diagnosis support and guidance!

 

[J_C]

You're welcome! The bullet shaped component is a thermal fuse. They wear out eventually and go open circuit even if they never got hot enough to reach their trip point.

 

[C420sailor]

Yeah, that thermal fuse pops usually when the fan motor gets old and the bearings start to go. The increased current draw pops it.

Since you have a new-ish motor, it’s probably just age making the fuse go.

I had your symptoms with an original motor. Replaced the resistor with new Motorcraft, and it lasted a few weeks. I pulled the motor out and it was stiff. Instead of buying yet another new MC resistor, I soldered in a new thermal fuse from Radio Shack. Good as new, that was a couple years ago.

 

[donalds]

I was 2 broke at the time To buy a new one
Took two resisters lol
so I had to disassemble my motor and clean and lube the bushings
And replace the resistor