Starter Switch Problem

[OKCM38CDN]

I went to start the jeep and batteries were dead. Recharge the batteries and while that was going on did resistance tests on positive lead. With ignition off I still had .350 ohms to ground. Troubleshot to starter switch. Took it out and opened it up and well you know the rest of the story.

So has anyone found a rebuild kit for these? I have an email in to John @ MWM to see if he has any. Figure to ask the question before taking file and emery cloth to the contacts. One of the Phenolic spacers is burnt and should be replaced. Need to find some circuit board material for that...

[cobra5]

Is the starter switch the same as the A1? Are you looking for the plunger? I tried John @ MWM and he told me he didn't have any. So I contacted Peter Debella and he had the plungers in stock. Hope this helps!

[OKCM38CDN]

I got as switch from John, both contacts and plunger were a mess, changed it out and adjusted per the M-38 manual and all is good...

[RICKG]

A little late, but I made up a few spare insulators.
http://willysmjeeps.com/v2/modules/gall ... .sized.jpg

[whydahdvr]

@OKCM38CDN:
I think I may have the same issue with the starter plunger on my M38. It's been getting harder and harder to start it. I suspect corrosion on the contacts or something with the plunger as that's what the symptoms indicate to me - repeated pressing of the starter foot button seems to improve the contact after it has been sitting a while. The jeep begins to start more easily after that. But it has been so offing humid and wet here in Massachusetts - and the jeep sits for long periods of time - that there may be other issues at play too, and it's taking a lot longer each time to get the strong electrical contact to start the motor.

Thanks!

[OKCM38CDN]

I got a NOS switch from John @ Midwest Military and fixed the problem right up. Works great now.

Trying to take the switch apart only goes so far. Special solder on the contacts...

[whydahdvr]

Thanks. That was my plan as well. What's the adjustment you have to do that you mentioned?

[wesk]

You should each confirm which starter (early AutoLite MBP4301UT, late AutoLite MCZ4001UT, late Delco X10483). The switches differ.

[OKCM38CDN]

Adjustment for the starter I found in TM 9-8012, Chapter 3, Section XI, Para 149c...

c. Adjustment. Loosen the jamnut (fig. 63) on the setbolt in
the drive pinion shifting yoke shifting lever. Depress the starter
pedal as far as possible. Adjust the setbolt in or out until the
starter switch makes a good contact, and tighten the jamnut.
Release the starter pedal, wait a few seconds, and try the pedal
again. If adjustment is correct, the starter will operate properly.

I realize this is the M-38 Manual, but it is exactly the same setup as my M-38A1 has. I made the adjustment per the manual and works like a charm.

Wes, I told John that I needed a starter switch for an M-38A1 after a discussion of the contacts, insulators and such and he sent me a switch. It is a little bit different in that the body of the switch appears to be molded plastic and the switch is newer, I think the NOS box was dated 1965. But it works as required and bolted right on with no modifications.[/b]

[wesk]

As I said above each member of this discussion should try to properly ID the model # of the starter they are discussing. For example, I already showed three possibilities above.

1 - Early M38 MBP4301UT

2 - Late M38, all M38A1 / M170 MCZ4001UT

3 - M38A1 / M170 Delco Remy X10488

Now Hal mentioned he used late M38/M38A1 switch and listed the switch adjustment in the M38 manual which if you read starting with the beginning of the Starter Chapter "Sect. 11 Starting System" Par 147 b. list the starter model as MCI-4001UT. If you look the same topic up in TM 9-8014 for the M38A1 "Sect. 11 Starting System" Par 154 b. It lists starter models Delco X10483 and Autolite MCI-4001UT but has no switch adjusting data. Now if you look at both the ORD 9 SNL G-740 dated SEP 55 it lists the three starters I listed in my last post

early AutoLite MBP4301UT, late AutoLite MCZ4001UT, late Delco X10483

. If you look in the ORD 9 SNL G-758 dated Sep 56 for the M38A1/M170 it lists only the later two starters I listed in my last post

AutoLite MCZ4001UT, late Delco X10483

. Not surprising the TM 9-1825B dated 1952 does not show either MCI-4001UT or MCZ-4001UT. The MCZ4001UT is found in it's own manual TM-9-2920-215-35.

[whydahdvr]

Wes,
Without pulling the starter out, how do I ID which one I have? I poked around yesterday but couldn't read anything on the visible parts of the body of the starter.

I'm going to look at the manuals to see if I can find identifying marks on mine but seem to recall that the best way was the number of teeth on the starter motor.

UPDATE: I was able (blind eyes last night trying to ID it) see the data plate. I have a late Auto-Lite. MCZ4001UT.

Thanks all!
Josh

[whydahdvr]

Update:
I connected with George at AJP. He said that the late-model starter switches are getting really hard to find. He recommended pulling it apart, taking some pictures to share with him so he can talk me through refitting it.

I'll see what I can do and share here what I find. The jeep sits at a shared family home so it may be a while and a drawn out process to get this project done.

Thanks.

[wesk]

Just use the correct manual for the MCZ4001UT, TM 9-2920-215-35, and you'll have no need for outside help.

http://www.willysmjeeps.com/v2/modules. ... it&lid=188

[whydahdvr]

Will do.

Thanks Wes.