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late style stock 24 volt light switch.
Posted: Fri Jul 01, 2016 12:50 pm
by Bobber
When I turn the switch on I hear a springing sound, which I believe is the internal breaker being activated. Then the lights don't work, but every 20 seconds I hear the spring sound and the lights blink and volt Gage needle pulsate back and fourth once. I also read these switches were unserviceable.
Does this all sound like my switch is bad, just checking. Thanks
Posted: Fri Jul 01, 2016 1:41 pm
by 4x4M38
Rusty,
It sounds like the breaker tripping. Age and abuse can damage the switch
as well as the breaker.
Bretto has taken his apart and refurbished the innards and bypassed
the breaker. Search the threads and you'll find it. I'd try that before I
chunked it.
I mean, you don't have anything to lose at this point, right?
Take care,
Posted: Fri Jul 01, 2016 1:49 pm
by Bobber
Thanks, I'll give it a try.
Posted: Fri Jul 01, 2016 7:35 pm
by 4x4M38
Of course don't ignore the obvious.
You may have a short in the light circuit.
Just a question. Is your jeep 24 volts or 12?
Posted: Fri Jul 01, 2016 9:27 pm
by wesk
We have a case of 1st advice was preceded by 2nd advice. The switches are not very expensive.
1-Yes the switch has an internal circuit breaker.
2-When it persistantly pops then the FIRST step is to check your lighting circuits for a short or overload.
3-If you find a short or overload fix it and try the switch.
4-If you don't find a short or overload my advice is replace the switch. They are not that expensive.
5-If you still must play with the switch then the value of your time will dictate the wiseness of your choice. If you do eliminate the internal circuit breaker make sure you find another way to protect the circuit IE fuse or remote circuit breaker.
Posted: Sat Jul 02, 2016 7:26 am
by 4x4M38
Yep. Took me six hours to realize I left off first thing to check.
Thanks Wes!
Posted: Sat Jul 02, 2016 10:29 pm
by Bobber
I checked each circuit breaker, then removed the light switch and started jumping the hot pin in the plug with a fused jumper and found two pins were shorted out. looked up the pin letter and it told me it was the brake light switch on the master cylinder. Removed it, tested it, then replaced it. Now it all works. The cycling of the circuit breaker had me a little confused, not ever dealing with those. That's why I thought it was a circuit breaker, but when I started moving the load wire from the circuit breaker to the other circuit breaker and the problem followed. Then I expanded my search. Thank you Gentlemen.
Posted: Sat Jul 02, 2016 10:43 pm
by wesk
Were you able to locate these illustrations in my photo album?
Also this manual can be applied to the later switches:
http://www.willysmjeeps.com/v2/modules. ... _album.php
Just use this pinout:
Keep your eye open for any deals on this really late model switch:

She's a bolt in replacement for your existing switch.
Posted: Sun Jul 03, 2016 5:56 am
by 4x4M38
It would feel weird having anything hooked up to a 65 year old
vehicle with a button marked "enter".....
Just saying.

Posted: Sun Jul 03, 2016 9:15 am
by skyjeep50
My '50's M38A1, a 70's bobtail M35 and a 2000's Hummer. All three with the same light switch although the Hummer has push-buttons. Mix the switches around and they all work the same. M-series vehicles - you have to love the interchangeability of some of the parts. No need to fix something that isn't made to fix, replace, that's the way it was designed.

Posted: Sun Jul 03, 2016 4:07 pm
by Bobber
yes I did use those illustrations, I use a lot of your pictures and illustrations

. Thank you for your pictures and information. I haven't seen much jeep stuff around these parts. Maybe I'm not looking in the right spot, I do keep my eyes open for parts though.
Thanks.
Rusty.