• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Thermal Fuse on 97+ XJ???

9

99greenjeeper

NAXJA Forum User
Location
Edmonds,WA
My HVAC fan is only working on the #4 position. 1,2,and 3 give me nothing. I know it has to do with the Thermal Fuse and I know where that is on a pre-97 XJ but don't know where it is on my 99 Classic. If anyone can help me it would be much appreciated.

-Dave
 
Dave,

Sounds to me like it is not a fuse but the blower motor resistor block. That is located under the dash behind the right kick panel on a 2000, probably the same location on the 99.

Good luck,
Tom
 
Can anyone walk me through finding the blower motor resistor block and what I should do to see if this is my culprit??? I have very little electrical experience on my XJ.


thanks,
Dave
 
if the blower only works on high, that means the blower motor is good. if none of the other speeds work then the resistor is bad. 12 volts run directly from the switch to the blower motor that gives you high speed. for the lower speeds the switch sends current through a series of coils in the resistor, depending on which switch position, makes the different fan speeds. sounds like you dont have any current leaving the blower resistor. the resistor is located in the heater case on the passenger side behind the black "bubble" shaped shield. do not run the blower with the new resistor just hanging down under the dash. it will burn it out quickly. it needs the cooler air from the blower to pass over it to keep it cool.
 
someone here has a writeup, i just can't recall who. it is the blower motor resistor pack. I had the same exact problem on my 2000. turns out all the resistors were good but one of my wires was coroded. remove, clean, reinstall and it worked like new. it is under the glove box.


Searched and found it....not "exactly" the same cause he has an earlier jeep but everything is in the same place.

http://www.geocities.com/chmwatson/FAQs/Jeep/HVAC-fuselink_fix.html
 
I tested my thermal fuse today with a multimeter and there was no continuity. So I went to Radio Shack for a replacement. They only had thermal fuses rated at 144 degrees C. Reading my blown fuse, it says 110 C. Will this new one work fine?
Any help is appreciated.

thanks,
dave
 
jneary said:
if the blower only works on high, that means the blower motor is good. if none of the other speeds work then the resistor is bad. 12 volts run directly from the switch to the blower motor that gives you high speed. for the lower speeds the switch sends current through a series of coils in the resistor, depending on which switch position, makes the different fan speeds. sounds like you dont have any current leaving the blower resistor. the resistor is located in the heater case on the passenger side behind the black "bubble" shaped shield. do not run the blower with the new resistor just hanging down under the dash. it will burn it out quickly. it needs the cooler air from the blower to pass over it to keep it cool.
Click to expand...
your asking for help but have you tried what has already been suggested. it isnt uncommon for the blower resistor to go bad causing these symptoms. i see it often in the shop. it is easier to check what has been suggested than to tear things apart and guess.
 
Yes, I had already tried what was suggested and knew that my resistors where fine. I just replaced the Thermal Fuse with one rated at 140 degrees C and now all fan speeds work again. Hope it stays that way.
thanks everyone for input.

-Dave
 
jneary said:
your asking for help but have you tried what has already been suggested. it isnt uncommon for the blower resistor to go bad causing these symptoms. i see it often in the shop. it is easier to check what has been suggested than to tear things apart and guess.
Click to expand...

There isn't much difference from taking out the resistor pack to check it than there is from taking out the resistor pack to check or replace the thermal fuse. on my 93 the fuse in question is part of the pack .....

I replaced the fuse but the fix didn't last, probably because the blower fan was on it's last leg - my guess is it was not blowing enough air to keep the fuse cool and/or the blower motor may have been running hot as it slowly died?
 
Hi- I am a first time poster, been lurking for a while... I just wanted to say THANKS to everybody on this board - I had this same problem - the fan only working on highest position (#4) on my '00XJ sport.... I checked it out, and found that corrosion rusted away one of the coils contact points (the thermal fuse on mine was fine). I cleaned it up with the Dremel and soldered the whole thing back -- works like new!

This board is Great, and I just wanted to say thanks again.

Dave
 
bjoehandley said:
Sorry for reviving a dead thread, but my '98 Limited just did the same thing

When you guys had to replace stuff, was it factory or aftermarket, and how much was the cost on it?
Click to expand...
When I replaced the blower motor resistor I used Factory parts. I ordered these from MakeItMopar.com, they have a minimum shipping charge of $9.95 so you might want to shop around at local dealers too.

When I asked them for the part numbers this is the reply I got (these are the correct parts for a 98 and a 94).
"This resistor is for a 1998 Cherokee (not a Grand Cherokee). The part # is 4864957, and is available through Makeitmopar.com for $31.46. The 1994 Cherokee (Not Grand Cherokee) is part# 55036000, and is available through Makeitmopar.com for$5.21."

The after market replacements I found (at NAPA and Advance Auto) cost twice as much as this factory piece.
 
A cautionary side note to anyone that has had their XJ stored away for any length of time.
If you have any indication of mice being in the vehicle,ie: droppings,shredded paper, STINK, or carpet padding in spots where it shouln't be, you may want to pull your blower motor, check the area around the resistor pack and look for carpet padding, it does burn and as we all know the resistor pack gets "red" hot.
I found this in both my 90' and91'...luckily before it combusted.
I got curious on my 91' and took the little nest of padding and set it back against the "pack", turned on the blower....poof..it caught, just enough heat and air for combustion.
Didn't mean to hijack thread but seeing as we were here anyway...lol
 
You must log in or register to reply here.

Similar threads

U
Electrical issue
Replies
6
Views
2K
UltimateG
U
X
drivers door switches only work on accessory mode
Replies
7
Views
1K
XJJeepNewb
X
D
1996 4.0 No Crank, Starter Works When Jumped
Replies
17
Views
244
Anak
Anak
Root Moose
Restoring a Uniframe
Replies
7
Views
142
DirtySouthXJ
D
F
99 XJ V8 Swapped, now door's will unlock but won't lock
Replies
3
Views
157
FreeRoller16
F
Back
Top