$2.00 Blower Motor Resistor Fix

I found this on some other site and it was quite useful ..... its for a TJ but worked perfect in my 96 XJ if its a double post please delete




Got a 97-99 TJ with a bad blower resistor? We’re going to save you up to $60.
Does your blower motor have two speeds, high and off? Chances are good you’ve got a bad blower motor resistor. Good news, it’s an easy fix. Bad news, the dealership wants over $60 for the part. At least that's what our local parts department decided this little platinum and jewel encrusted gem was worth. Some of you may be lucky enough to have a stealership that only wants $40. Others may be even luckier and find one at a parts store for about $25. That price is much easier to swallow, yes, but what if we told you that you can fix your old resistor for $1.95. That’s better than $25 and a helluva lot better than $60.

Installation

1. Start by removing the kick panel on the passenger side under the dash with an 8mm socket.

2. Don’t forget the two on the bottom.

3. With the kick panel out of the way, the resistor is easily accessible. Slide the red plastic clip back, and remove the connector.

4. With an 8mm again, remove the two screws holding the resistor.

5. Carefully remove the resistor.

6. Here is the resistor out of our Jeep. Make sure yours is this style, not the thin credit card type, before trying to fix it.

7. With needle nose pliers, bend the tabs holding the cage on the resistor and remove the cage.

8. With the cage removed, we can clearly see the thermal fuse. This is the part of the resistor that fails most of the time and is our $2 fix. With a volt/ohm meter, check for continuity across the fuse. If you have no connection, the fuse is bad and lucky you, the resistor can be fixed.

9. Head over to your local Radio Shack, or other electronics supplier, and pick up a new thermal fuse. Make sure you get one with a similar heat range to the 130°C the factory fuse is.

10. Cut the bad fuse out with wire cutters. Cut close to the fuse so you have some wire left over to work with.

11. Rather than risk blowing the new fuse while soldering, we’re suggest using crimp on connectors.

12. Remove the plastic from the connectors so it doesn’t melt while in use on the Jeep.

13. Crimp the new fuse in place. Make sure the colored cone end is oriented the same way as the old fuse (pointing left in the picture).

14. Carefully put the cage back on checking the fuse for clearance.

15. As one final test before installing, check for continuity between the outside pins on the resistor. If you have a connection, put the resistor back in the Jeep.

Final Thoughts

Success! We have all 4 fan speeds again. And we saved $58.02 by not supporting our local stealership parts department. Disclaimer: If your resistor is fried in some other way, this won’t fix it and you’re going to have to cough up the money for a new one. But 90% of the time this will work, and for $2 it’s worth trying. Also if you have a newer TJ, your resistor is different and this won’t work. But your part is cheaper so stop complaining.

http://www.moabjeeper.com/articles/technical/listing.cfm?articleID=515
The guy who wrote that might appreciate the credit, and you can see the larger pics there as well.

One thing I'll add to this: if your blower motor resistors start to fail, expect the blower motor itself to go at some point. IIRC, after swapping out three resistors (each with a progressively-shorter lifespan) the blower finally bit the big one.

I'd venture a guess that your blower motor was failing the whole time, causing resistor failure. Going to have to replace both those this week just so I can get some heat without full-blast fan...

Jim www.yuccaman.com/jeep

hubs97xj said:

http://www.moabjeeper.com/articles/technical/listing.cfm?articleID=515
The guy who wrote that might appreciate the credit, and you can see the larger pics there as well.

Click to expand...

Good point ... thanks for the page it came from ... I had it saved locally ....

it might also be worth noting that replacing the thermal resistor is best done in conjunction with replacing those resistive elements. They're usually nasty and not at the proper Ohm spec. You can see in the pictures that where the springs join the spade conectors there's corrosion. I cut them off, clean up the spade connectors and solder replacement coils in.

Mild steel springs from the hardware store cut to the proper length make good replacements.
Use your ohm meter to determine the proper resistance.

Excellent info!

I would replace the thermal fuse, but replacing the resistor coils themselves is past what I would spend my time on. There are 3 different manufacturer's blower resistors in the rockauto catalog, all under $9. Between that and my worry that the solder may come undone from the heat, or that the replacement resistor coils may not have the same temperature coefficient, I'd just buy a new one instead of soldering new coils on.

EDIT: one of them is $32, apparently I can't read! The other two are under $9.

Figure this is better than a new thread, my 2000 is giving me issues too. I can get all 4 fan settings to work but I have to turn the switch to 4 then back it down. Sometimes it will take 10 seconds or so for the lower settings to run too. Sound like the resistor?

kastein said:

Excellent info!

I would replace the thermal fuse, but replacing the resistor coils themselves is past what I would spend my time on. There are 3 different manufacturer's blower resistors in the rockauto catalog, all under $9. Between that and my worry that the solder may come undone from the heat, or that the replacement resistor coils may not have the same temperature coefficient, I'd just buy a new one instead of soldering new coils on.

EDIT: one of them is $32, apparently I can't read! The other two are under $9.

Click to expand...

My adventure into making a new resistor pack was born from a lack of new ones for my Aspire. Seriously, they don't exist, and kia/ford/mazda was dumb enough to encase them in cermic/plaster, so every one yopu find in a junkyard is also rusted on the inside.

It's not burned to the ground in the 18 months since I replaced them with springs of a similar wire size. I used silver solder and a torch to solder them on, so they're not coming off from normal airbox temps.

Colorado S14 said:

Figure this is better than a new thread, my 2000 is giving me issues too. I can get all 4 fan settings to work but I have to turn the switch to 4 then back it down. Sometimes it will take 10 seconds or so for the lower settings to run too. Sound like the resistor?

Click to expand...

no, I would guess blower motor, high resistance in the brushes is requiring more current to get the fan to spin initially, then after spinning you can feed it the lower current. If the resistor pack was done you would have nothing but "high" which essentially bypasses the resistors and connects the switch directly to the blower motor. Of course you may also want to double check all of the connectors, mine were burnt and charred at the back of the HVAC controls and did all sorts of wonky things.

87manche said:

My adventure into making a new resistor pack was born from a lack of new ones for my Aspire. Seriously, they don't exist, and kia/ford/mazda was dumb enough to encase them in cermic/plaster, so every one yopu find in a junkyard is also rusted on the inside.

It's not burned to the ground in the 18 months since I replaced them with springs of a similar wire size. I used silver solder and a torch to solder them on, so they're not coming off from normal airbox temps.

Click to expand...

Oh, that makes a lot of sense. What you did, not what the manufacturer did. I never thought it would be possible to have more mid-year splits than the XJ till I tried to fix the tranny cooler lines on a neighbor's 03 Mazda 626. Bought the stupid lines (they rust out just like XJ ones, but worse) and went to install them and they were completely different. Fortunately going back to the dealer with the VIN got the right ones (they were in stock, they fail so often) and they only charged the difference in price between the one we returned and the right one.

</derail>

kastein said:

Oh, that makes a lot of sense. What you did, not what the manufacturer did. I never thought it would be possible to have more mid-year splits than the XJ till I tried to fix the tranny cooler lines on a neighbor's 03 Mazda 626. Bought the stupid lines (they rust out just like XJ ones, but worse) and went to install them and they were completely different. Fortunately going back to the dealer with the VIN got the right ones (they were in stock, they fail so often) and they only charged the difference in price between the one we returned and the right one.

</derail>

Click to expand...

yeah, the aspire is a bit odd. Built by Kia for Ford using a bunch of Mazda parts. Then Kia filed for bankruptcy in like 99 or some such and all the not mazda or ford parts dried up. Encasing the resistor pack in plaster was a new one. I had to bust it all up to get at the spade terminals, and found out that every coil had rusted into pieces. but I've got less than 1K bucks in this thing and it gets 40+ average.