58 Cj5 Headlight Switch Question

More elec. problems,,,

When I bought this Jeep all lights worked fine, later no lights except headlights work. I've checked every connection I can find, fuses etc. Then thought maybe the switch could be the problem. In testing it
seems weird to me. With the ignition on and light switch off the hot wire at the primary fuse end OK, but the
tabs also hot, but not the other end of fuse. The fuse is good. With switch turned on tabs test 0.30v to 1.20v or so, also the opposite end of the fuse the same.
The switch is kinda cruddy looking with rust around the knob end of the threaded shank against the switch body. There are wires connected to the two tabs on the right and to the tab closest to the knob end. The remaining tab without a wire tests negative.
It's Greek to me ? Any ideas ?


Thanks, John ,,

 

Glenn, thanks for you response. The jeep was re-wired to 12v by a retired electrician, nothing works unless the ignition is on. He said he done it that way
to help deter thieves and possible battery drain if he forgot to turn the lights off, it also has a hidden switch that cuts off power to everything. I think the switch
may have been wet in the past by the looks of it. Also has two plugin adapters under the hood for normal driving or towing hookup. Maybe I should hook it to my truck
towing harness to see if works that way ?

Thanks ,,,, John

 

Sounds like the PO took something that was easy and made it harder. Older Jeeps are simple and are made that on purpose, why make it harder. I can see making a hook up for flat towing, and putting a switch to disconnect the battery, but prefer to leave the wiring harness alone. I did use trailer wire to wire the stop and tail lights so the color code was the same as all trailers and can be traced easily.

 

Think about this for a minute..? No matter what, If you have power at the primary fuse end but not at the other end of fuse (as you stated) then the fuse is no good. The fuse may be barely touching under one of the ends that will show some voltage but will not pass current. A test light (as stated) will give you better mileage in solving this problem. With the light switch OFF and key ON, the tabs should have no power to them unless the internals of the light switch are bad or you have power back-feed.

 

Mix-up in the diagnosis somewhere. Needs to try again with a test light and report back.

 

What Walt said x2. Good Luck.

 

I tried the test light as Glenn suggested, same results. I just replaced the switch with a new one of same type. Same thing as old one.
Beats me ,,,,,

 

No problem Glenn, I appreciate the tip ! Power to the fuse on the new switch same as before, every thing the same. I'm going to test all connections
I can find with the test light, got to be something simple, I hope. Every thing was fine when I bought it, maybe a fuse I haven't found yet or a bad ground.

One thing though I found a wire to a headlight that a blasted mouse or rat had chewed into, fixed it. Same thing on my ATV, chewed wires. I put out
a bunch of pizzen, no more problems since. I hope the varmint suffered.

Could be part of the problem.

Thanks,,
John