Difficult Start

Discussion topics on Willys Overland M series vehicles
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PK
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Difficult Start

Post by PK »

I have a difficult time starting my 1951 M38. When I press the starter foot switch, it seems as though the batteries are dead. If I hold the switch it turns very slowly and usually I can get it to start after several minutes and tries. When it starts it runs well.

I have charged the batteries.

I cleaned the terminals and where the ground attaches to the battery tray.

I get 24.5 volts with a digital meter with one lead on the starter terminal and the other lead to ground.

I had the starter checked at a local starter shop it checked out ok.

Any help is appreciated.

Thanks
PK
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wesk
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Post by wesk »

If your ignition timing is advanced more than 5 Deg's BTDC then that will cause the slow starter rotation.

If the timing and point gap/condition is good then:

If the shop that checked the starter also opened and inspected the switch on top of the starter then you have a grounding issue. Is the ground strap between the right front engine mount plate and frame in place?
Image

If the strap is clean and tight then it's time to do a voltage drop check of the entire circuit.
http://vernco.com/id606.htm

24.5 is not a fully charged dual 12 volt battery system. 25 to 26 would be more correct. With engine running at about 1200 RPM you should read 27.5 to 28.5 across the batteries.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
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PK
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Post by PK »

Wes,
Thanks for the advice. I will check these things.
PK
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bucky
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Post by bucky »

Check battery voltage thru both batteries in series, compare to readings aquired off the starter post.......If there the same ,charge the batteries. If a drop is noted. use you meter to test at every connection bac toward the batterys. Watch for correct voltage to find your cruddy connection. Check you gruond strap for high resistance connections even if it looks clean. Looks can be decieveing. Also dont overlook terminals already cleaned check them all wirh your meter as well. Having learned the hard way.... bucky
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DFoley
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Post by DFoley »

wesk wrote:If the strap is clean and tight then it's time to do a voltage drop check of the entire circuit.
http://vernco.com/id606.htm
Wes I can not get this link to work...can you check it and see if it needs an update.
Dan
1951 M38
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wesk
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Post by wesk »

Dan,
Here's his main index page: http://www.vernco.com/index.htm

And here's the link to the voltage drop checks
http://www.vernco.com/sparks/id606.htm
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
ocwd
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Grounding/Bond Strap

Post by ocwd »

Wes,

Is the metal grounding strap in your picture the only metal type on the M38? What is the correct length and thickness of that strap? I have a bunch of metal type bond straps in the garage and want to make sure that I keep a suitable strap for my Jeep. Is there a TM that has drawings of this strap?

Dave
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wesk
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Post by wesk »

None that I know of. The basic rule is it must be of adequate gage to handle the load. In this case it must be able to move the same amount of current as the big positive battery cable that is hooked to the starter.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
ocwd
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Bond Strap

Post by ocwd »

Thanks Wes. I'll just keep a couple of different sizes that are long enough to go from the engine mounting plate to the frame. In looking at your picture, I think I have one very similar.
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