Heater fan resistor

#1

A friend of mine has hugh speed heater fan only on his Dodge Dakota. ('03).

they used to have a resistor under the hood on the heater assembly, but I can’t find one. Does anyone out there know where it is?

#2

Remove the glove box and you’ll see it mounted to the blower motor housing.

Tester

#3

Thanks Tester, I was looking under the hood. Now I wonder wher the turn-signal flasher id on MY ‘96 Dodge 2500 van. I am goin’ to look at the manual as soon as I get the supper dishes done!!!
Never mind, my manual tells me it too is under the glovebox liner.

#4

Elly, If A New Resistor Makes The Fan Work Properly For A Few Days …

… and then goes back to “high only”, the fan itself probably needs to be replaced and another new resistor. A worn and tired out fan motor possibly blew the resistor. A good way to go is to find a low miles 03 Dakota (or as new a model year with same parts as you can) in a “take-it-off-yourself” salvage yard. You can practice on their truck, first. Many yards mark and guarantee the parts to work. The ones on my wife’s Intrepid required only removing/installing eight screws, total! However, time and patience to access them was necessary.

#5

Friend of mine is having a problem with the resistor on the heater motor for his BMW. It’s a dealer item only…cost…$45…for a simple resistor which cost BMW about $.50.

#6

The New One for The Dodge Intrepid Was Quite An Elaborate Piece Of Hardware - Only $20

#7

I’ve replaced one of those on the BMW, it is not a simple resistor (and it isn’t easy to replace). It is a heat sinked flow and temperature measuring unit with machined aluminium cooling blades, a 5 pin interface, and is fairly beefy/hefty. And 45 dollars is a pretty good price for this part if he got it from the dealer.

#8

Friend of mine who is a EE…said it was just a simple resistor (maybe we’re talking of a different component for a different BMW). He bought the part from BMW…then measured it…then got the same resistor from work…and used that one…works fine. He would have just used the one from work IF he new the resistance. Of course the one used in his car wasn’t coded…just plain gray.

#9

at this point I have removed the glove compartment door but there are still about 6 screws to go and then I am not sure the glove box will come out, are you sure the resister is back there??

#10

Does it not have stops on it that can be squeezed or removed to allow the box to swing out and down? Been there done that on 2001 Town and Country.

#11

I would require a lot of explanation from the EE. Don’t picture a little resistor like you see soldered to a circuit board. These have to be able to dissipate a lot of heat. The ones I have seen are nichrome wire coils like you see in a resistance heater. The wire in these alone would cost more than $.50.

#12

The glove box in my 96 Dodge van just pops out but this Dakota is something else. The box is stationary, only the door swings out but that doesn’t get you anywhere. He hasn’t been here for a day or two, I’ll keep lookin’.

#13

Hey, Elly, Look Under The Hood And See If That Dakota Looks Like This!

I’m not sure that this is a 2003, but that’s what I searched. Maybe this is an older model. It looks like it’s on the firewall. This is an easier place to work, if it’s there.

Click this link:

let us know.

#14

Well, I appreciate your help, but our truck does not look like the picture. In the pic it looks like part of the heater housing is under the hood. On ours there is no part of the heater under the hood. My friend went to O’reilly’s today to buy a resistor and they told him it must be a dealer item, I can’t believe this.

#15

I don’t have a wiring schematic for this truck but on many vehicles the fan speed may be controlled by more than one fuse; one for high speed and one for all of the rest.
Have you checked all of the fuses?

Something else to consider is that if a fuse is blown or the resistor is fried, this could be caused by a dragging blower motor. As an analogy, think of plugging a bunch of Xmas lights into a wall socket and the circuit breaker tripping now and then.
In this case replacing the fuse or resistor may be a short term fix and it may fail again soon.

#16

well it is not my truck but I don’t think the motor is dragging. As for the fuse, you might just have something there, I will check.

#17

You Can’t Tell If The Motor’s Dragging. The Only Symptoms Are Blown Resistors.

The fan motor works mighty fine and then Blammo! Back to one speed, high only!

#18

Here are the instructions, and drawings, of how to get to the blower motor. Follow the wires from the blow motor to the resistor pack. http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c15280041e0f

#19

The fan motor may sound like it’s running fine but that doesn’t mean it’s not dragging, and dragging means more current which means more heat and a tendency to blow fuses or fry resistors.

The best way of determining if the motor is dragging is to use an ammeter and check the current being drawn. On high speed one could probably figure on 5 amps, give or take, on a used motor. If the amp draw gets into the 9 or 10 range then the motor is dragging.
(And keep in mind that a blower motor, just like any other electrical device be it house or car, has a surge current when it is first turned on. If a blower motor is pulling 9 amps on high speed it could very well be sucking up 15 amps when first activated.)

#20

Well, I can’t see the resistor in the picture so I guess we’ll keep looking. Thanks everybody!! If anyone else can help, please do.