1952 M-38 Starter Issue

MoxM38 · Post by **MoxM38** » Mon Dec 07, 2020 6:19 pm

Gents,
This is my first post to this forum, although I've been following it for a few years. Excellent tutorials from all...I am grateful for them. Currently, I am working on a very puzzling issue trying to get my starter to turn-over. Here are the details:

Background: I recently had my motor rebuilt due to a blown head gasket and a couple bent valves and a cracked piston. It was time...had 31 years on the previous rebuild. Prior to the current rebuild, it used to start up just fine with no issues. It is a 1952 M-38, serial # MC 65209 and block # RMC 83861 and has the original 24V system and accessories...there have been no modifications. It really used to run like a champ prior to the causes that led to the rebuild and I never had a problem with starting it.

Problem: The starter will not turn-over at all. I took lots of pictures prior to disassembly and have a copy of the MC 38 Maintenance Manual, along with researching many of the other manuals while surfing the different forums.

These have been my installation/troubleshooting steps:

1. Reassembly of all items needed to turn over the engine (basically minus the radiator, no coolant, no plug wires, no air cleaner or vent lines). Tried to turn over and no life out of the starter at all. Next...

2. Took off generator, starter, and voltage regulator and cleaned up all connections, ensured bare-metal to bare-metal grounds on starter and voltage regulator to frame. Opened up starter and checked that the starter switch closes when engaged and cleaned up all contact points (they were a bit worn). Wire brushed all electrical contact points on outside of starter (where positive battery cable and cable to regulator connect). Reinstalled, tried it again, nothing. I even ensured that the foot plunger fully engaged the starter pinion and starter switch...it does. Next...

3. Removed starter and sent away for rebuild thinking the brushes might be bad. Once returned, reinstalled, same result....must not be the starter! BTW, it is a MCZ 4001 UT. With a voltmeter, I checked the current flow: I have about 12.6V from each of the two batteries and as they are combined in sequence, I have about 24.9V of power at the starter bolt with a good ground on the starter. Next...

4. I looked up under the dash panel and none of the three circuit breakers have been touched and nothing has been adjusted or moved there during the rebuild. When the battery switch is on (24V flowing), all of my lights and accessories work. I've tried bypassing the starter connection using a screwdriver across the two posts....I'll get a little surface spark when I touch but no life at all out of the starter. My ignition switch is set to the on position, although my understanding is that this switch only controls power to the distributor and doesn't need to be on to turn over the starter. No "next" at this moment....

I am absolutely stumped. Before I go fishing around under the dash and dissecting the wiring there, I wanted to see (hope) if there was something very simple that I am not thinking of. Vehicle electronics was never my strong point but I thought I understood them enough to have gotten this going. I followed all posts on this forum that relate to this topic (plus a very good one from 16 July 2013 entitled "Puzzling 1952 m38 won't start." I followed it carefully and thought it would answer my issues....unfortunately not.

BTW: I have been trying to post pictures to this post on all my steps but the process to put in photos has been so difficult, I gave up after two days!...I really need to post this. I cannot figure out how to insert a picture into this post. I do have pics on my album: http://www.willysmjeeps.com/v2/modules. ... _album.php

Any assistance would be appreciated...my fingers are crossed for a simple no-brainer!

Mike_B · Post by **Mike_B** » Mon Dec 07, 2020 7:06 pm

1. Does the engine turn over by hand?

2. Does the starter turn the engine at all?

3. Does it turn over with the spark plugs out?

4. Have you bench tested the starter motor to confirm it runs?

5. Your 24v system should read about 28 volts at the batteries...if it reads 24+ volts you need to charge them up.

Mike B

Post by **wesk** » Tue Dec 08, 2020 12:19 am

Your drop box photos do not display because the Drop Box site requires our web site to sign in to Drop Box to retrieve them. This is a common problem with most photo hosting web sites. Follow the simple directions with you mjeeps web site photo albums and post them from here. If you are using an I phone or I pad yes it is difficult to post photos. Our mjeeps web site forums are old school and work best with PC's and lap tops. I can only guess at which photos you wanted in which part of you post above.

Eng full view

Starter

Ign Switch

Circuit breakers

I noticed you mentioned checking current but you posted voltage reading. The Big 3 test ranges we deal with in electrical systems are:

1 - Volts (Pressure): measured with a volt meter.
2 - Current (Load): Measured with an amp meter
3 - resistance: measured with an Ohm meter.

To clear up expected voltage at starter terminal first let me state we have a 28 Volt electrical system. This means all things working well the system when being used tries to regulate it's average voltage at 28.0 to 28.5 volts. We use a pair of 12V batteries that gives us a nominal 24V system. These batteries fully charged with no load (system off) applied will usually measure 24.5 to 25.5 volt. Depending on the overall condition of your electrical system, when the master switch is turned on these batteries will read 23.0 to 24.0 volts. After starting with a good electrical system the voltage will climb to 28.0 to 28.5 volts.

A few pre-steps one should take when installing a freshly OH'd engine and accessories:

1 - Bench test the starter. (We all believe the starter rebuilder was smart enough to do this, but check again)

2 - Continuity check the kick switch.

3 - Confirm you installed the ground strap on the right front engine mount. (yes, I see the added strap you have at the front of the starter)

4 - It may sound rediculous but check for the correct polarity. Negative ground!

To initiate your troubleshooting I suggest starting with (pencil & paper for writing down all these readings!)

1 - battery voltage reading with master switch off and all accessories turned off. I check this twice. once with the plus Volt Meter lead on the + terminal and the neg lead on the Neg terminal then again moving the negative lead to the chassis ground.

2 - Battery voltage reading at the input terminal on the kick switch with master switch off and all accessories turned off.

3 - With master switch off and all accessories turned off, connect plus lead of your voltmeter to the output side terminal of the kick switch and neg lead to chassis ground. Manually engage the kick switch and record the voltage reading.

If you have full system voltage at this step the problem is in the starter.

Give us the readings you find so we can be more helpful!

This is your starter photo. The side of the kick switch with the two heavy wires is the input side and the side of the kick switch that attaches to the solid copper connector is the output side.

MoxM38 · Post by **MoxM38** » Tue Dec 08, 2020 1:53 am

Thanks for the speedy replies.... Mike_B, I've got answers to your questions below:

1. Does the engine turn over by hand? Yes, it turns over by hand.

2. Does the starter turn the engine at all? No, the starter shows no life at all.

3. Does it turn over with the spark plugs out? No, spark plugs in or out, same result.

4. Have you bench tested the starter motor to confirm it runs? I did not bench test it. Kaiser Willy's rebuilt it and that was one question I specifically asked them and they said it was bench tested and should be a "drop it in and go."

5. Your 24v system should read about 28 volts at the batteries...if it reads 24+ volts you need to charge them up. I will charge them up and/or get new batteries. It seems if they were a bit low they would at least engage the starter somewhat, but I am no electrical expert

The batteries are several years old (at least 8-10 years)

I've got some testing to do per Wes' guidance and will get this information soon. I will also follow your guidance on the insertion of photos....they are very useful in me describing my issues.

Post by **wesk** » Tue Dec 08, 2020 10:59 am

Was the kick switch rebuilt with the starter?

Can we assume you have the same model/PN starter, kick switch, starter drive gear and flywheel you had when it use to start easily?

MoxM38 · Post by **MoxM38** » Tue Dec 08, 2020 1:01 pm

Kaiser Willys (KW) told me that everything was completely rebuilt with new parts, to include the switch. They state the starter drive gear matched the one I turned-in (same number of teeth) and the flywheel was reused, only resurfaced by the machine shop when the block was rebuilt. Flywheel teeth were not replaced.

The starter is slightly different than what I turned-in, but the mechanics at KW assured me that it was compatible. What I took off of the Jeep (which worked fine prior to rebuild) was a PrestoLite MCZ-4007-UT (I had to turn-in the starter core as part of this exchange) and what came back was an Autolite MCZ-4001-UT. Interestingly, when I review the TM, it states that an AutoLite MBP-4301-U came on it from the factory...so I was not previously using an original starter.

I will take complete electrical measurements tonight per your previous instructions. As I think more about your guidance about how many volts I should be receiving at the starter (~29V versus the 24+ I was getting), I now recall that the spark I received when I touched the two posts together with a screwdriver was awfully weak...very tiny spark versus the large, startling spark I have received in the past with normal 12V batteries when I accidentally touch the battery posts together

Also, below is a test of posting a photo from my Album to a forum post...I hope it works.

MoxM38 · Post by **MoxM38** » Tue Dec 08, 2020 8:38 pm

Wes,
I have line-item answered your very insightful troubleshooting steps below, I am hopeful we are getting much closer to the solution:

1 - Bench test the starter. (We all believe the starter rebuilder was smart enough to do this, but check again) I was going to exhaust the other alternatives before doing this...not sure if I am equipped to do a bench test off the vehicle...KW assured me it was bench tested.

2 - Continuity check the kick switch.Also, assuming KW bench tested this as they said they did. If no joy after the voltage tests, I'll pull it off

3 - Confirm you installed the ground strap on the right front engine mount. (yes, I see the added strap you have at the front of the starter) My concern is that my new motor mounts are all rubber, I don't think I'd get as good a ground as its current position on the voltage regulator to chassis, which is where the ground was prior to rebuild, see below

These are the new mounts, they are all hardened rubber without a metal plate surrounding it--like the old replaced motor mounts

This is where the ground strap was originally. All connection points are metal-to-metal, right to the frame

4 - It may sound ridiculous but check for the correct polarity. Negative ground! All checked, good to go!

Since a picture is worth a thousand words and almost like being here, I have attached pictures for the steps that you recommended to ensure I was testing where you suggested:

1 - Battery voltage reading with master switch off and all accessories turned off. I check this twice. once with the plus Volt Meter lead on the + terminal and the neg lead on the Neg terminal then again moving the negative lead to the chassis ground. Done, see below for results next to the pictures. NOTE: I have had both batteries on a battery tender regularly:

This is Battery #1 in Engine Compartment, readings terminal to terminal. Note that there was much fluctuation in readings while I was holding it here, as much as +/- .4V

This is Battery #1, readings from positive terminal to negative chassis ground, same fluctuations as above

This is Cowl Battery #2, readings terminal to terminal

2 - Battery voltage reading at the input terminal on the kick switch with master switch off and all accessories turned off.

Voltmeter positive on starter input, negative on chassis ground, battery master switch off, foot switch off

3 - With master switch off and all accessories turned off, connect plus lead of your voltmeter to the output side terminal of the kick switch and neg lead to chassis ground. Manually engage the kick switch and record the voltage reading.

Voltmeter positive on starter output, negative on chassis ground, battery master switch off, foot switch pushed in

Note that I also took the following readings:

Master switch on, voltmeter positive on starter input, negative on chassis ground, foot switch off

Master switch on voltmeter positive on starter output, negative on chassis ground, foot switch on. That minus sign fluctuated on and off, not sure why. During all of these tests, there was absolutely no life out of the starter whatsoever.

My first reaction to this is that I might have two inoperative batteries and maybe they should both be replaced. I would like to note that previous to these tests, I had regularly been getting 12.75 volts out of each battery with the same results of no life out of the starter....just FYI...

Post by **wesk** » Wed Dec 09, 2020 1:39 am

Rick,
Actually the MBP starter was only used thru engine serial MC74419. The MBP was the small frame, open face starter that mounted with 1/2" bolts and used the 124 tooth flywheel. The MCZ4001UT was used from eng serial MC74419 & up as well as on the M38A1. It is a large frame, closed nose starter that mounts with 5/8 bolts and uses the 129 tooth flywheel. I haven't found an application for a MCZ4007UT.

Now that we have test results it appears that your kick switch is not functioning. Was that kick switch installed on the starter when KW bench tested it? Next step is to OHM check the kick switch. Disconnect batteries. Remove the two cables from the input side. Unfasten the copper bar from the output side. Take an ohm reading across the switch with the pedal not depressed. Should read open circuit. Then take the reading with the pedal fully depressed. Should so continuity with a very low ohm reading.

Post by **wesk** » Wed Dec 09, 2020 1:54 am

A note on the battery voltages. When batteries are used as a pair in series they must be closely balanced and perfectly match in physical structure. This means two identical batteries, the same age and voltages within .5 volts of each other.

MoxM38 · Post by **MoxM38** » Wed Dec 09, 2020 4:50 am

Wes,
OK, I will next give the kick switch the ohm test. Also, my Engine serial is #RMC83861, looks an engine transplant had occurred sometime in this little guy's past....early model jeep frame with late model engine.

It appears I am now in the market for some new batteries. My current batteries are your typical car batteries and are thicker than what may have originally been in there....this observation comes from the battery hold down frame not fitting correctly.

Recommendation: Can you recommend a type/brand of battery that would do best and where I could get it? Also, what cold cranking amps should I look for?

Thanks for all your help... it's reassuring knowing that us hobbyists aren't totally alone in this adventure!

Xamon · Post by **Xamon** » Wed Dec 09, 2020 6:19 am

you should be able to "bench" test the starter in place, hook a set of jumper cables negative from battery to starter ground and touch the positive to the positive feed post on the starter. it should spin. If I remember right the kick pedal engages the drive sprocket so it won't try to start it will just spin the starter.

MoxM38 · Post by **MoxM38** » Wed Dec 09, 2020 7:23 pm

OK Team, here's the latest from tonight's efforts.

Here I checked resistance btwn input and output posts, kick switch is off

With the kick switch engaged, resistance is showing some

I also decided to check the voltage once again, here combined batteries, meter positive on input terminal, negative on chassis ground

When the kick switch is engaged, the voltage drops to this. Is this normal or an indication of bad batteries? Or something else?

Xamon suggested connecting the combined batteries to the output terminal, which I am doing here by touching positive cable (25.1V) directly to output terminal. Tiny little spark, no life out of starter.

What do you recommend next, Wes? I will order new batteries, what do you recommend that will fit my battery trays and have proper cranking amps? I think I will also pull the starter again and look at the kick switch. Thoughts?

RonD2 · Post by **RonD2** » Wed Dec 09, 2020 7:51 pm

Hi Rick,
Before you buy new batteries, why not know for sure? You might consider hauling them to your local auto parts store and ask them to test them, usually for free. They can check them 9 ways from Sunday, especially to see if cranking amps are up to spec. Just a thought.

And I've resurrected so-called dead batteries with a battery tender. It's a good tool you might consider having to maintain long-life for your batteries.

Good luck!

MoxM38 · Post by **MoxM38** » Wed Dec 09, 2020 8:03 pm

That's a good point, I will do that to check. What cranking amps do you think I should have in each?

Also, both batteries have been on a battery tender for a very long time....they were both purchased in Sept 2012, over eight years old.

I'd put them on a charger but I don't like to do that with them unattended.

RonD2 · Post by **RonD2** » Wed Dec 09, 2020 8:08 pm

Rick,
The battery should be labeled somewhere with "CCA" --- Cold-Cranking Amps --- and an amperage number, maybe in the range 550-650. The battery test will reveal what it's really doing in comparison to the label number. A "fail" will be quickly evident, label or no label. Yes, volts are important, but it's amps that turns that starter motor over.

I couldn't help but notice you have "Everstart" batteries, the Wal-Mart Special. They get noticeably consistent horrible reviews, even when new, much less 8 years old like yours.

My battery tender can take several days, 96 hours or more, to resurrect a dead battery, if it can be done. Some do, some don't.

Good luck!