You know, when you're riding around after dark and you hit the dimmer switch to make the high beams come on, and lights just go out... even if only for a second or so... it can shake your nerves up a bit. So what would make an '85 CJ-7 act this way? Dirty/bad/corroded dimmer switch? Does anyone have experience with this? Is a switch cleaning a good starting point or would you recommend replacing it? Could it be something else? Thanks. Mark.
I had this same thing happen in a motorhome with a Ford Chassis. There is a thermal switch within the switch that prevents overload on the wiring, I would replace the switch, much easier than trying to repair it.
Kevin in Iowa
99XJTrailMarker wrote:
The aftermarket dimmer switches are total garbage. The pricks don't last me 2 years. I have gone through 3 since 2000 and the last one up and quit on me last summer at 1:00 AM or so on the start of a 3000 mile trip with a cop inspecting my lights while it happened! The one before that quit when doing a light check just before another 2 week camping trip.
I now have mine just cut right out and the wires spliced for low beams with a button for my driving lights I use as high beams.
I am not sure I want to replace it with another junk part, I might just go with a switched relay and a push button on the dash.
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: N>The thermal breaker is in the headlight switch, not in the dimmer on the CJ's.
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: N>You can unplug the connector on that foot switch and the lights will go out (happened to me once when I kicked it loose!). You might try cleaning the contacts and make sure the connector is tight.
My money is on the dimmer switch itself.
The thermal switch is a self resetting circuit breaker, no electrical problem was ever cured, by a larger fuse, in a fused circuit! nor a new thermal switch (which is part of the headlight switch) it was stated in the 1st mess. that the lights went out, then came back on.Too much load!plain and simple..find the problem.
75 CJ-5 original owner...
The dimmer switch is the problem.
If it was the thermal breaker, the lights would continue to flash on and off. Been there, more than once. This wouldn't 'only' happen while he was hitting the dimmer switch.
Mine go bad 'exactly' as he describes.
'Real' easy to test, just put on the highbeams and watch. If the breaker is going, it will start flashing for sure.
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/06I remember the feeling well.
You've got corrosion at the dimmer switch, either at the connector or within the switch itself. I've had it happen on my `79 CJ5 a couple of times. I let mine go for too long once and had a little smokey fire going where the harness meets the connector -- a little scary at highway speeds.
The switch is easy to replace: two screws, perhaps driven into plastic blocks set in the floor on yours, and a 3-wire harness connector. Examine the connector carefully, clean/replace/rebuild as needed. Wirebrushing away corrosion is only a stopgap fix because the rust comes back now that the plating is gone. Pack the connector full of bulb grease when you reassemble to slow the decay down. If you take the wires out of the connector be sure to label them so you can put them back the right way after lunch.
Because aftermarket electrical parts can be crappy, as Mike notes, buy the best you can and figure on replacing the thing every couple of years.
-- "I defer to your plainly more vivid memories of topless women with whips....r" R. H. Draney recalls AFU in the Good Old Days.
(Failure to follow posting direction repaired. Standard charge: two-fifty.)
Yes, the headlight breaker is thermal actuated and is self resetting.
Yes, no electrical short is cured by higher-rated over-current devices.
No, replacing a thermal breaker can cure an electrical problem if the problem is the breaker itself. Breakers can age out and become "soft".
The OP stated that the headlights went out briefly when he switched from low to high beams. This is a symptom of a bad dimmer switch and is a common problem in CJs.
An overload on the head lamp breaker will cause it to cycle continuously while overloaded, not blink once only when switching from low to high.
Yes, his problem is simple, but you misinterpreted the symptoms for something more complex.
-- "I defer to your plainly more vivid memories of topless women with whips....r" R. H. Draney recalls AFU in the Good Old Days.
I got tired of that damn switch on my C-10 Chevy and replaced it with a dash mounted switch.
It's just a simple two way switch (SPDT) and can easily be replaced by a 120vac paddle switch from RadioShack. Just get an amperage greater than the fuse rating. :)
Your looking for one that has ON-ON without a center off and three tabs on the back.
The guts of that switch are almost exactly like those in a ballpoint pen. Each time you press it turns and eventually the whole thing wears out.
Did somebody suggest a larger fuse?
Bill and I both said the dimmer switch was the problem. Replace the dimmer switch.
Switch replacement corrected the problem. Thanks for all the input. I tried cleaning the terminals first, since one or more posters declared the replacements to be junk. The original lasted over 20 years and
190,000 miles. If I can get half of that out of a $6 part, I'll be more than pleased. Mark.Thanks for the follow up. Good luck with the replacement.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >Excellent news. Thanks for getting back to us.
-- "I defer to your plainly more vivid memories of topless women with whips....r" R. H. Draney recalls AFU in the Good Old Days.
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