Distributor problem (points) 1950 M38

ServiceManual · Post by **ServiceManual** » Sun Jun 30, 2013 5:30 pm

I have run into a small problem getting my 1950 M38 jeep willys to run that I was hoping to get some assistance with.

Electrical problem: Not receiving spark to the spark plugs and the distributor points keep frying. I traced power all the way from the battery to the solenoid to the starter/ and power from the ignition switch is getting to the coil. something might be wired wrong and is causing the points to fry. I tried turning the ignition on (turning the motor) trying to see if I could even see a spark between the points but I didn't. I also turned the ignition key to accessories and there is power getting to the coil (12V). I am stumped as to what is going wrong.

I replaced the starter to a 12 V starter, replaced the distributor points, condenser, rotor, cap, wires, and plugs, I also replaced what I think is the solenoid (box between Battery and ignition switch)
I traced power from the battery forward and it reaches the coil. and it is putting out power to the distributor however, the points are still frying and not allowing for power to continue on.

The previous owner installed an alternator and changed the battery to a 12 volt battery.

Thanks for helping. Im looking forward to putting another willy on the road.

Post by **wesk** » Sun Jun 30, 2013 6:49 pm

Sounds like either you have a bad condenser or the coil you are using is a 6 or 8 volt coil and you're not using a ballast resistor. Post some photos of the right side of the engine and the firewall.

artificer · Post by **artificer** » Sun Jun 30, 2013 9:37 pm

What exactly do you mean by frying....welded together or just depositing like this?

ServiceManual · Post by **ServiceManual** » Sun Jun 30, 2013 9:48 pm

The point contacts look good but the copper spring on the pivoting point lost its tension and is extremely pliable. plus the .020" gap became a 1/4 " gap after. I took pictures of the right side but I cant figure out how to post them..
Thanks for the help....

Post by **wesk** » Mon Jul 01, 2013 7:50 am

Overheating is caused usually by leaving the ignition switch on for a long period when the points are closed. But as I already posted overheating will occur when you use a 6 volt coil in a 12 volt system without a ballast resistor.

6 volt coils were the standard since the 1930's. They delivered maximum amount of energy that the contacts can handle in the old conventional point type ignition systems. As 12 volt systems became popular the points could handle any more energy so the manufacturers took two paths. Some used the original 6 volt coil and added a ballast resistor between the coil and the switch. The others designed a new coil they called a 12 volt coil which was really a 6 volt coil with a resistor built in. The result was two 12 volt coils on the market. One that has stamped on it "12V" "USE WITH EXTERNAL RESISTOR" and the other which just says 12 volts.

If you have the "Use with external resistor" coil and you do not have a porcelain resistor mounted usually on the firewall between the switch and the coil then the points will overheat as will the coil. Some of these arrangements include a resistor bypass during starting which delivers a hotter spark when cranking the engine but reverts back to the use of the resistor with the starter not turning.

Your photos cannot be posted here from your personal computer. They must be loaded to a host site first then you can link them using their URL to your post.

I opened a photo album for you here on our web site:
http://www.willysmjeeps.com/v2/modules. ... _album.php

Here's a tutorial on how to looad the album:
http://www.willysmjeeps.com/v2/modules. ... _album.php

ServiceManual · Post by **ServiceManual** » Mon Jul 01, 2013 12:09 pm

Im going to try installing a new 12V coil this weekend and look over everything again. I dont have a ballast resistor so i think that might be it. Ill keep you updated tho. Thanks again for the help guys.

oilleaker1 · Post by **oilleaker1** » Mon Jul 01, 2013 6:11 pm

Your point set should have a spring steel band next to the copper band that you talk of getting flimsey. Burned up points are the contacts as pictured. If yours are not damaged there, you have something else going on.

ServiceManual · Post by **ServiceManual** » Mon Jul 01, 2013 7:00 pm

Yea, I must have something else going on because the contacts of both sides of the points still look good but after I tried turning over the motor once, I looking inside the distributor again and saw burnt debri piled up along the bottom edge and the copper spring was stuck onto the condenser insulation. kind of melted onto the insulation on the wire of the condenser. that's when I pulled it apart and noticed it was very pliable. and I also noticed the points were far apart and had to tension (spring back) to them.

Post by **wesk** » Mon Jul 01, 2013 8:05 pm

The issue hasn't changed. The contact set is still being overheated. Instead of the ground passing thru the two contact heads to ground it is passing through the copper strap to ground. Sounds like your insulator for the terminal connection has failed.

ServiceManual · Post by **ServiceManual** » Tue Jul 02, 2013 12:02 pm

Ooooooohhhhhhh , your absolutely right! I never thought of that. I'm still going to get a 12v coil, this weekend and I'll check and change the insulation blocks on the stud (distributor housing) and where the copper spring attaches and ill make sure its good before trying again.

ServiceManual · Post by **ServiceManual** » Wed Jul 24, 2013 1:46 pm

Update... I still have no luck getting the jeep to start. I replaced the points (again) tightened everything down snug, replaced the coil with a 12V coil with an integrated ballast resistor and still no spark...

I read in a few different websites that the m38 was equipped with a 24V system that differentiated it from its predecessor. That included two 12V batterys in sequence.Des anybody know if that might be my problem? I only have one 12V battery right now.
Thanks.

Post by **wesk** » Wed Jul 24, 2013 6:53 pm

I think you have already established that your M38 is not stock and that it has already been converted to 12 volt so no sense in frying all the 12 volt parts with a pair of batteries putting out 24 volts.

You should work on getting us some photos of what you have. I opened an album for you and listed a tutorial to show you how to load the album in my first reply. Try that first.

ServiceManual · Post by **ServiceManual** » Fri Oct 11, 2013 6:09 pm

Hey guys, I need some help with my 1950 M38 again. I managed to finally get spark on my #1 plug. I rebuilt the carter W-O carburetor completely and reinstalled it. I primed the carb bowl with fuel and cranked the engine. I get 4 LOUD pops out the exhaust within 10 seconds of cranking. I am stumped and I don't know what else to troubleshoot next. Any advise helps at this point. Thanks in advance.

A couple things I already tried are: I used starter spray, I checked the plugs for signs of flooding, and i checked that the rotor was pointing at #1 lead while in TDC.