Blower Motor

artickid · **Posted:** Wed Jul 09, 2008 9:27 pm

My blower motor only orks on high, anyone else have this happen? What is the most likely fix?

Joe Romas · **Posted:** Wed Jul 09, 2008 9:32 pm

There's a resister that's easy to replace and inexpensive that's gone bad.

artickid · **Posted:** Wed Jul 09, 2008 9:50 pm

Where is the resistor located and can you get one at the parts store?

maxxgraphix · **Joined:** Wed Mar 26, 2008 8:11 am **Posts:** 53

Typically located in the air ducts near the blower motor. I doubt a parts store would have it.

mrkake · **Posted:** Wed Jul 09, 2008 11:42 pm

Check out this thread over in the general discussions section. Same problem as you are having.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=33902

danoid · **Posted:** Thu Jul 10, 2008 8:17 am

Chrysler part number is 05139719AA, it should be under $20. Open the passenger glovebox and slide it to the side to disengage the hinge. You'll see it right there.

edit - I still have my failed one sitting on my desk. It's about the size of a business card with a large connector glued to one end. Four large terminals and one small.

Once I found out how this works (dropping voltage by wasting power in resistors to slow the motor down) I was appalled. Does anyone know a more efficient way to control this motor? Any way we can PWM this like my computer fans?

Joe Romas · **Posted:** Thu Jul 10, 2008 9:09 am

danoid wrote:

Once I found out how this works (dropping voltage by wasting power in resistors to slow the motor down) I was appalled. Does anyone know a more efficient way to control this motor? Any way we can PWM this like my computer fans?

On the bright side you get more heat in the winter :oops:

Maybe Turbo Tim can come up with a EHCM (Electronic Heater Control Module) :wink:

Turbo Tim · **Posted:** Thu Jul 10, 2008 9:31 am

Yup, it’s already been done. Your cost in parts alone is about $160.00 and you still get to make your own circuit board and include a enclosure (and design the electronic circuit, of course your time is free).
GM and I believe the Cadillac Northstar cars have a PWM speed control. I’m sure there are others too.
The bottom line is to reduce the power in the motors electrical windings to control the fan speed. A PWM does this be sending varying width electrical pulses which the motors inductance averages it and the end result is the total power needed for that speed.
Aside from a mini transmission, the little resistor pack in the air duct wins hands down.
It's much more reliable than a bunch of electronics, smaller, costs less, and gets the job done.
The amount of heat it gives off in nothing in the big picture.

If you were to measure the total amount of power needed to spin the fan at a given speed using the resistor pack vs. an electronic module, you would find that the resistor pack is the most efficient. Reason is that the fan needs “X” amount of energy. The electronics also adds it’s needed amount of energy too, so the total is more.

The only place a PWM is better in this application is if you need extremely slow fan speeds……

If your worried about trying to save energy, turn off the fan and roll the window down.

Threeweight · **Joined:** Mon May 14, 2007 5:57 pm **Posts:** 679

I've yet to do the blower recall on my Jeep (haven't wanted to deal with the hassle of stripping off mods to avoid the warranty headaches). Is this resistor related to the "fire danger" cited in the recall?

chadhargis · **Posted:** Thu Jul 10, 2008 3:50 pm

Ah....BEAUTIFUL!

My blower won't work on anything but high, and I've not had an chance to surrender my Jeep for a day (or more) to get it fixed.

Hell, I'll just pay for it out of pocket and fix it myself.

Called the dealership, and they have it in stock. YEAH!

Thanks!

artickid · **Posted:** Thu Jul 10, 2008 5:10 pm

What kind of price does the delarship charge for one of these buggers?? :?:

chadhargis · **Posted:** Thu Jul 10, 2008 5:27 pm

danoid · **Posted:** Thu Jul 10, 2008 9:42 pm

Turbo Tim wrote:

If your worried about trying to save energy, turn off the fan and roll the window down.

Yup, I'm already doing that.

Also I did a little digging, almost any car with automatic temperature control (at least the Chryslers) have a PWM fan for stepless fan speed changes.

chadhargis · **Posted:** Sun Jul 13, 2008 3:17 pm

Replaced the $17 resistor board....problem fixed!

I love this place!

Blower Motor

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