Blower speeds failing over time

[Tom_G]

Aloha all!

99 Ranger XLT.

A few years ago, all 4 positions for the interior blower worked just fine. Then, with no warning, the lowest setting stopped working, leaves 2,3,&4 as options. Time passed, and 2 stopped. Now 3 has stopped working as well, leaving only full-blast arctic. I'd kinda like to have at lease one option back; preferable, all 4. Thoughts?

 

[Dirtman]

You need a new blower motor resistor. They cost about 20 bucks, takes about 10 minutes to replace. It's under the hood on the lower part of the hvac box.

 

[RonD]

+1 ^^^

Current part number is 4L5Z-19A706-AA
fits 1995-2011 Rangers

If you are wondering what happened
There are 3 resistors in this device, each sets one of the speeds below FULL speed, seen here: https://s3.amazonaws.com/rparts-sit...2e62e8f1/db706e7670d612abc1bceb19b4f15ee0.JPG
Each coil is a "resistor"
You lost 1 resistor at a time, which is unusual, but not unheard of, usual failure is a main lead fails and no low speeds just high/full speed which uses a separate wire

These are located in the Air Stream of the blower/fan to keep them cool, they get hot, like the coil in a toaster, or light bulb filament, but not THAT hot, lol, so over time they will "burn out", normal wear and tear

So there is no underlying issue of why it failed, just happens over time

 

[Tom_G]

Thanks!
I've watched a couple of videos on the replacement, and pretty much in each one they're commented about the sad state of the connector as well. Should I plan on changing the connector at the same time? I suppose, as long as I'm in the neighborhood, there's no reason not to.

 

[bobbywalter]

+1 ^^^

Current part number is 4L5Z-19A706-AA
fits 1995-2011 Rangers

If you are wondering what happened
There are 3 resistors in this device, each sets one of the speeds below FULL speed, seen here: https://s3.amazonaws.com/rparts-sit...2e62e8f1/db706e7670d612abc1bceb19b4f15ee0.JPG
Each coil is a "resistor"
You lost 1 resistor at a time, which is unusual, but not unheard of, usual failure is a main lead fails and no low speeds just high/full speed which uses a separate wire

These are located in the Air Stream of the blower/fan to keep them cool, they get hot, like the coil in a toaster, or light bulb filament, but not THAT hot, lol, so over time they will "burn out", normal wear and tear

So there is no underlying issue of why it failed, just happens over time

there can be an underlying issue...the motor wears out and gets increasingly resistive....and blows out a new resistor in short order as it gets to the end of its life. ifthe new resistor fails in less then 6 months or you have to beat on the motor to get it to go....its new motor time as well.

 

[Dirtman]

Thanks!
I've watched a couple of videos on the replacement, and pretty much in each one they're commented about the sad state of the connector as well. Should I plan on changing the connector at the same time? I suppose, as long as I'm in the neighborhood, there's no reason not to.

The connector is somewhat open to the elements and because the resistor generates heat, yea the connections can go bad. Some resistors come with a new pigtail already, some don't. Pop it off and inspect it. That's the only way you'll know if it needs to be replaced. Been a while since I did one but it's just 2 small bolts, 5.5mm or 7mm I think and you can pull the resistor out of the hvac box, then pry the connector off. If you do replace the connector, solder and heat shrink the new wire splices do not use crimps.

 

[adsm08]

If you do replace the connector, solder and heat shrink the new wire splices do not use crimps.

I like to crimp and backfill with solder. It give the ease of a crimped connection and the security of solder.

I have found on larger gauge wires if I don't strip what seems like an excessive amount the splice comes unwrapped during soldering. A crimp eliminates that.

 

[Dirtman]

I'll have to give that a try. Either way, not a connection you want exposed or loose by just using a cheap crimp alone.

 

[JohnnyO]

I had to put one in my Sport Trac a few months ago. In my case it was on the inside firewall above and to the left of the glovebox door. Electric motors only know full speed so to slow them down you need a resistor.

 

[Tom_G]

aloha all!

Well, that was a very annoying process. But, for $14.19 and a couple of hours' inconvenience, I now have 4 fan speed again!!!!!

Mahalo to all for the advice!

 

[Dirtman]

Congrats. And we here at TRS really appreciate when someone responds that the problem was fixed. It helps other people when they search for issues. Alot of people get answers and never respond back which helps no one. So big thumbs up buddy!

Hope you stick around.

 

[Tom_G]

Congrats. And we here at TRS really appreciate when someone responds that the problem was fixed. It helps other people when they search for issues. Alot of people get answers and never respond back which helps no one. So big thumbs up buddy!

Hope you stick around.

Well, with a 99 Ranger under the garage, and my favorite mechanic closing up shop, I think I'll be around a bit more!

 

[royallichter]

I'm curious how finicky these are, or, how bad the stock fan motor is in terms of variability? The truck heats and cools just fine so maybe it's just me being picky. But, I put in a new one about a year ago because mine only functioned on the highest speed as well, but I still feel like the first three speeds aren't really there. Has anyone heard of a bad resistor out of the box?

 

[Dirtman]

Has anyone heard of a bad resistor out of the box?

Yes, any one that doesn't say motorcraft on the box...

 

[4.0blue98]

True!!! I put a resistor in a few month back and didn't replace the connector. It was pretty nasty but I thought I cleaned it up pretty good. The new resistor was not an MC and it feels like speeds 1 and 2 are the same, 3 and 4 are fine. Not sure if it is definitely the resistor but probably is.