Can the blower motor resistor unit still be faulty despite it looking ok?

Bob.Gibson

Bob.Gibson

TJ Enthusiast
Supporting Member
Joined
Sep 8, 2019
Messages
159
Location
New Zealand
The blower on my 05 TJ is showing all the symptoms of faulty resistor.
Only goes on one speed (second one) but blows at full speed.
I have pulled the resistor but all the coils look fine.
Can the resistor unit still be faulty despite it looking ok?

Cheers

Bob
 
Ok thanks everyone. I've ordered a new one.

Just curious the unit looks very basic where does the fault in them occur?
 
Bob.Gibson said:
Ok thanks everyone. I've ordered a new one.

Just curious the unit looks very basic where does the fault in them occur?
Click to expand...

I think the internal resistors just go open.

In speed 4, you get no resistors, 3 gets you one resistor, 2 gets 2 resistors, and 1 gets 3 resistors. If a speed requires a resistor that has failed, that speed won't work, so they work their way down... Lose 3, then 2, then 1.

If you have 2 and 4 but not 3, I don't think the resistor is your problem.
 
Mine is three speed but only works on 1
The resistor unit is the style that has the coils and what looks like a diode or a resistor.
All the coils are intact.
 
Just replaced mine, I've seen others pull their old ones and the plastic looked melted or the connectors burnt looking — mine looked new minus the dust and cob webs — replaced with one from amazon, and voila! it all works.
 
I think I have found the problem. Installed a new coil pack but the problem remained.
Took the switch apart and the copper plate on the end of the shaft had chewed out the locating indents on the shaft.
I could have repaired it with JB weld if a replacement was not available but new switch will be here any day.
 
  • Like
Reactions: AMS417
Bob.Gibson said:
I think I have found the problem. Installed a new coil pack but the problem remained.
Took the switch apart and the copper plate on the end of the shaft had chewed out the locating indents on the shaft.
I could have repaired it with JB weld if a replacement was not available but new switch will be here any day.
Click to expand...
I assume you had to buy the entire unit (with all 3 knobs) vs. just the fan speed switch? I could not find just the switch for my 06' while I was researching, they sell just the switch for the older TJ's not the newer ones — luckily the coil pack solved my issue, but I was preparing to swap the switches too. I'm sure that will go eventually as well.
 
It might be worth checking the condition of the blower fan while you're at it. My jeep was exhibiting the bad resistor symptoms so I went ahead and ordered both a new resistor and a new blower motor. When I pulled the fan to replace it I found the fan was really difficult to turn by hand and the bearing was just about shot. The resistance caused by the fan was messing with the resistor's ability to do what it does. The new blower motor fixed the problem so now I have a back-up resistor when/if the current one fails.
 
2006_LJ said:
Just replaced mine, I've seen others pull their old ones and the plastic looked melted or the connectors burnt looking — mine looked new minus the dust and cob webs — replaced with one from amazon, and voila! it all works.
Click to expand...
Usually caused by the fan motor going bad from its windings shorting together once the shellac insulation starts breaking down. Once things start melting & burning up it's time to replace the fan motor.
 
  • Like
Reactions: 2006_LJ
2006_LJ said:
I could not find just the switch for my 06' while I was researching
Click to expand...
It's a very common switch shared with a ton of vehicles like the Ram 1500. You can find them under $10 shipped. I just replaced mine a few weeks ago.

Edit: never mind, looks like they changed in 2005
 
This site contains affiliate links for which Jeep Wrangler TJ Forum may be compensated.
Fred85 said:
It might be worth checking the condition of the blower fan while you're at it. My jeep was exhibiting the bad resistor symptoms so I went ahead and ordered both a new resistor and a new blower motor. When I pulled the fan to replace it I found the fan was really difficult to turn by hand and the bearing was just about shot. The resistance caused by the fan was messing with the resistor's ability to do what it does. The new blower motor fixed the problem so now I have a back-up resistor when/if the current one fails.
Click to expand...
I wish I knew of this when changing mine, I'm all for preventative maintenance and not having to open / touch the same thing twice.
 
Top Bottom
Back