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Hello all, having some trouble with the operation of my light switch. For what's it's worth, my truck has been "upgraded" to have turn signals.

TM9-8030 outlines the use of the light switch and the various positions. I'll use this as my guide. For those following along with our home game I'll post a picture of the light switch from the manual.


Turn on Service headlights: lower right switch to position F and simultaneously move upper lever to position E. This works. Headlights come on and I can switch between high and low beam.
Turn off service headlights: upper switch to position C, and lower left switch to J. Nope. I have to move the lower left switch to position H, and then my panel (dash) lights and marker lights (which are now turn signals) come on.

This is about all I can do. I can't turn off all the lights on the truck. I can turn off some of the lights, but not all of them. Before I started playing with the light switch to assess the light situation, all lights were off. Also, my unlock switch doesn't seem to move anymore. It's stuck in the "lock" position.

What's going on here that I am not understanding?

Bad switch or two wires shorted together. H is park and the instrument and markers SHOULD be on if the top lever is at E only. Top lever straight up and NO lights should work.

Well, get the lock working first. The switch itself is not user friendly to take apart.

C, J and G should be no lights anywhere

Use the unlock and go to D. Here the brake lights work, the turn signals if correctly done work in this position. This is your standard daytime public road driving switch position

Use the unlock to go to E, move J to K. standard position for public road driving at night. Brake lights (if you step on the brake), tail lights, headlights and turn signals and dash lights (on low) are all on.

Moving from K to H and the headlights go out, Brake lights still work, tail lights are on. in front the parking light comes on in the light housings.

Check all that, then we can worry about the blackout positions.

Is there some way to take the switch apart? Mine is not like the one in my original picture with the screws on the face. It seems to be a two part unit: an out case which has had some component pressed into it.

ez8 wrote:Is there some way to take the switch apart? Mine is not like the one in my original picture with the screws on the face. It seems to be a two part unit: an out case which has had some component pressed into it.

A photo would help.

06boblee wrote: A photo would help.

I can do dat.

The one in the manual, that you posted is the earliest of these "modern" military light switches. You could get them apart. The one you pictured below is a later version of the switch. Those,I have never had luck getting apart

After couple days of careful analysis, I think I can get the switch apart if by using a BAH. However, that would render the rest of the unit inoperable.
Therefore, the remedy of this problem appears to be a cash injection to a parts supplier. If it turns out I can get this apart, I guess I'll have a spare!

Thanks for the help, all.

The switch is common and easily obtained. I eventually found a wiring diagram for the internals of the switch to use for troubleshooting. I found the one I had was bad and replaced it. I know how to open one of the swaged closed ones. Getting it sealed again is 'difficult'.

You could try one of these,,

06boblee wrote:You could try one of these,,

That looks too simple to operate.

I like when my hobbies frustrate me. It's a wonder I don't play golf.

I think the pushbutton switch is cool. My current service army buddies tell me they are rather 'problematic' in use.

Did you change the bulbs in the marker lights to dual filament bulbs and do they have three wires going to each light? If not then you will not have turn signals AND marker lights. You may want to go over the wiring again. Did you use the original equipment turn signal flasher unit mounted on the floor plus the one on the steering column?

It was the light switch. I replaced it with a new one from Kaiser Willys and all functions performed as advertised.

Having never operated a three lever light switch before I wasn't sure what the feel was supposed to be, but comparing to the new one there is a definite difference. My old light switch didn't pop into the various positions - it would smoothly shift from one to the other. Makes me think that something internally has been worn down quite a bit. Doesn't matter, though. The new switch works like a dream.