M38 on/off switch problem

joebuck · Post by **joebuck** » Fri May 19, 2017 6:19 pm

Howdy, got a little dilemma which is not hard for me with 52 Willys. My on /off switch was on the blink so I bought a new one from Kaiser. Thinking I connected the four wires exactly like old one based on how switch turned over. Well I didn't No power when I switch on. So any advice.? Here are some pics. Well I'll try later on pics

joebuck · Post by **joebuck** » Fri May 19, 2017 6:42 pm

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joebuck · Post by **joebuck** » Fri May 19, 2017 6:46 pm

4x4M38 · Post by **4x4M38** » Fri May 19, 2017 8:34 pm

Joe,
Depending on the version of the switch and the M38 wiring you could have
a couple different wiring configurations with the military switch.

Your replacement doesn't look anything like the original you took out.
More importantly, the taped red wires don't give us any idea whether
they are correctly wired per the original.

Are the wires marked with the metal tags? If so, that helps.

The military switch wiring diagrams are available here on this site.
With that you can see how the original switch was wired, and see if your
replacement is the same.

Take care,

Post by **wesk** » Fri May 19, 2017 8:41 pm

What part number was your new 4 wire switch? I have never seen one with red wires and tape.

I'll assume for now that you have a surplus Greek 4 wire and failed to buy the short Packard to Douglas connector harness.

This is what the rear view of the switch will show:

Do yourself a favor and but this adapter harness:

Saturn Surplus used to list both the switch and adapter harness. I just looked at their site and no longer see the switch. In the harness section
http://www.saturnsurplus.com/electrical/wire.htm I found:

Wire Lead - 8" - 1 Douglas-2 Packard . 171209r91 2590-00-561-6105 $4.50 Y-14

Which will take care of #11 Douglas to A & B Packard.

I do not see the other 2, but they are not hard to fabricate using all the available parts at Saturn.

4x4M38 · Post by **4x4M38** » Fri May 19, 2017 9:38 pm

Here you go:

http://m.ebay.com/itm/M38-M38A1-M715-M3 ... iid%253A17

Note it also includes that Douglas connector to tie 85 to
when not in use.

joebuck · Post by **joebuck** » Sat May 20, 2017 6:23 am

Thanks guys for the help. Now it's clear the Mistake I made was not buying the wiring harness with the plug. I just bought the plug andhad a guy at work soldier the wire leads to back of plug posts. If I can correctly line up wire to correct plug hole , will the route I'm going work for temp fix till correct harness come in? ( I need to move my jeep today according to the wife!!!!)

4x4M38 · Post by **4x4M38** » Sat May 20, 2017 7:24 am

Assuming your jeep is 24 volts and the rest of the wiring is factory.
Yes you could temp it. A and C have to have power.
B and D are power out to the circuits. Look carefully at Wes' diagrams
and make sure your wires are going to the right places.

You don't want to fry anything.

joebuck · Post by **joebuck** » Sat May 20, 2017 8:07 am

Thanks Brian. Mission accomplish . And now all my gauges work. Well except gas. It's showing a 1/4 when it's really 3/4 . Just bought a new gas sending unit . Wonder if I have to calibrate it ? I just took out old one and popped in new one

Thanks Wes. Diagram was huge for me

Post by **wesk** » Sat May 20, 2017 11:44 am

If you you gain even a little from the site we enjoy providing it. The key is Manuals. If you don't use them you will always perform ignorant stunts that will always cost you more time and money then reading the book first would have cost.

Now let's talk about the book on gauges! If you haven't read it yet then you have spent money you may not have too to fix a problem that you did not know the cause of because you did not use the troubleshooting guide.

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