Has anyone else had troubles with the fan speed selector switch in a TJ melting down and not working right? Mine has melted enough that it had literally liquified and began to meld with the plug behing it. Is there a problem I should be aware of, or did i just get a bad switch from the factory? BTW I have a 1999 TJ 4cyl.
Thanks
The fan would run in the 1st, 2nd and halfway between the third and fourth position, the contact that melted out of the switch was the contact for the high position. I had trouble with this before and was able to rebuild the switch, however it melted down again. Just wondering how it got hot enough the melt and liquify plastic but not blow a fuse of some kind, this is what my biggest concern over this is.
It would appear from many posts here that the TJ switches are total crap. You can buy the whole assembly or make the parts guy dig down in his computer and just order you the switch itself. The switch is about $15.00.
There was another thread on this and if I remember right, the new ones out of the box were getting hot almost instantly so it might be a good idea to have the dash panel open to try them when going shopping.
What happens is a bad connection causes an arc. This is like an arc weld and is extremely hot. Because it is so localized, it can usually melt down the switch before heating up the wiring enough to melt the fuse.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >I don't want to scare you, but I think that your biggest concern is fire behind the dash. Melted plastic is a sign of heat, with electricity you get heat from current confronted with resistance. On a blind guess there's either a design flaw that allows a partial contact in the switch, an under-sized conductor in the switch, corrosion or poor mechanical contact between the connector and the switch, poor bonding between the wires and the connector contacts or a chaffed wire that is now too narrow to carry the current that the fan draws.
This site says that there were problems with the YJ series fan switches developing internal resistance and overheating: Dunno if the design flaw carries over into your TJ, but replacing the switch is obviously in your future anyway.
David Owsley wrote:
According to that guy that sells Jeeps and posts here it is really common, therefore it is a design flaw that 'should' be a recall item.
Fire hazard and no defroster control are both safety issues.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
I found out you could just buy the switch and not the whole assembly, I've replaced 3 so far. I quit having the problem when I quit running the fan on hi, just going to the 3rd setting. I'm guessing the fan motor draws too much current on hi and needs to be replaced, I just haven't done that yet. I also had to replace some melted wires.
Joe Carroll
2K-TJThere are some simple truths...And the dogs know what they are." Joseph Duemer
The motor can only draw too much on speeds 1, 2 and 3. When you go to high, it is supposed to be a low power trigger line for a relay in the TJ's from what I understand...
The older ones like the CJ7's pull full power through the switch on high.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
Well that shoots the crap out of my theory... At least I figured out how to buy just the switch...Back to the drawing board....
Joe Carroll
2K-TJThere are some simple truths...And the dogs know what they are." Joseph Duemer
Maybe that is the cause of the trouble, the switch makers put crappy contacts in because high wasn't a direct draw...
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Now I wonder if just replacing the switch and not the whole panel might be part of the problem. There may be something integral to that switch elsewhere in the panel that's not obvious. I don't have any of the proper diagrams so it's just pure guess work at this point.
Joe Carroll
2K-TJThere are some simple truths...And the dogs know what they are." Joseph Duemer
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