CJ2a Battery Question

Farm Willys

Farm Willys

Gear Grinder
Jan 10, 2021
17
Edgecombe County
First Name
Becky
Willys Model
  1. CJ
Willys Year:
  1. 1946
Hi have a CJ2A question.

What do you all think about changing to accommodate a 12 volt battery? My jeep is hard to crank in NC winter temps.
 
First, I'd check the battery connections, and the gauge of the battery cables. The cables need to be heavy 0 gauge for 6v. If they've been changed out at some point for the common smaller gauge 12v cables, they won't be up to the job.

Pete
 
Might also be the starter... I had a Studebaker lark that would barely turn over. Went through the entire electrical system trying to figure out why the battery didn't have the juice to crank it, new cables, batter, starter solenoid, etc. I finally pulled the starter, and found that it was so fill of dirt, crud, and dried grease that it wouldn't turn. The bushing in the nose of the starter was worn and sticky. Cleaned it out and lubed it up, and it cranked like a new car.
Also, for what it's worth, my Wagon with a 6-226 and 12v system (all new) still cranks very slowly when it has been left out in the cold. I think it's because of the heavier weight oil I have in the engine, which refuses to budge when its near zero.
Pete
 
X2 on the starter. Went thru this on an old generator/welder rig a few years back. Turned out that the starter was just plain tired. Got it rebuilt and no more issues spinning it over with a 6 volt battery. We did upgrade to an 8 volt battery and then adjusted the regulator so the generator would charge it correctly.
 
My Jeep has the 8 v as my uncle converted all his 6 v to 8 to help out. Some folks say there are issues but if the reg is set and related it does seem to help a lot
 
The 8 volt coversion is old school but it worked very well and you didnt have change anything but readjust the vr..Phil
 
Years ago my dad put an 8v battery in the 2a and set up the regulator. Had to put a resistor on the headlights as they burned out. Don't remember checking the starter.
 
Its the starter that needs the 8 volts so it will turn faster and does not drop the voltage at the coil so it sparks real good, thats the idea...Phil
 
Pete said:
Might also be the starter... I had a Studebaker lark that would barely turn over. Went through the entire electrical system trying to figure out why the battery didn't have the juice to crank it, new cables, batter, starter solenoid, etc. I finally pulled the starter, and found that it was so fill of dirt, crud, and dried grease that it wouldn't turn. The bushing in the nose of the starter was worn and sticky. Cleaned it out and lubed it up, and it cranked like a new car.
Also, for what it's worth, my Wagon with a 6-226 and 12v system (all new) still cranks very slowly when it has been left out in the cold. I think it's because of the heavier weight oil I have in the engine, which refuses to budge when its near zero.
Pete
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The starter has been rebuilt. Was hopeful this was the solution since during warm months it cranked up easy.
 
Farm Willys said:
The starter has been rebuilt. Was hopeful this was the solution since during warm months it cranked up easy.
Click to expand...
I watched some video a while back. Guy was taking a starter apart that had been rebuilt. Sounds like lots of things get missed unless you know your way around them. Not saying it wasn’t done right just a comment.
 
my 2A is still 6 volt and I had the same issues, very slow turning and slow to start . The starter was just rebuilt, new battery , new #1 cables. I finally narrowed it down to the braided ground strap from the frame to the engine. I also replaced my fuel pump with A fuel pump with the primer lever on the side. It helps in cold starts.
 
A better ground would be to run the -6 volt from the battery right to the starter and use the frame to block ground for the lights ect...Phil
 
WA7OPY said:
A better ground would be to run the -6 volt from the battery right to the starter and use the frame to block ground for the lights ect...Phil
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I kind-of prefer the original, ground wire from battery to motor mount bolt , braided strap from motor mount to engine. You could run a separate ground directly from the battery to the starter but the braided strap still needs to be properly maintained. It is very easy to over look.
IMG_8841.JPG
 
I am an aircraft system engineer for avionics and poor grounds are one of the most overlooked issues when there are aircraft system failures.
Folks forget the return side is equal to the high side on voltage. No good path of return for current either because of resistance or open circuits many times give similar outcomes. We measure grounds to milli ohms dc and if above those values we have to take care of it. So as noted a hood return circuit is as critical as the high side
 
Farm Willys said:
Hi have a CJ2A question.

What do you all think about changing to accommodate a 12 volt battery? My jeep is hard to crank in NC winter temps.
Click to expand...
I have two 1946 CJ2A's and I changed them over to 12 volts and replaced the generators with alternators And don't forget the ignition system and gauges, plus all the lights. I also went with a Pertronx high voltage ignition system. The six volt starter will relay spin the engine. It the starter is in good shape you will be all right. Just don't lean on the starter. If your wiring is old or in bad shape you could create a big problem, a fire.

Have fun. Whats better than having a Flat Fender? Having two Flat Fenders.

John
 
Blue Duck said:
I kind-of prefer the original, ground wire from battery to motor mount bolt , braided strap from motor mount to engine. You could run a separate ground directly from the battery to the starter but the braided strap still needs to be properly maintained. It is very easy to over look.
View attachment 90989
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Thanks will look at my cable and see how it is connected and the condition.
 
If the link doesn't work go to www.Jeepdraw.com & scroll down till you get to How to Series & Starter Diagnosis ~ here you will find a detailed outline of completely checking & diagnosing everything in the starter circuit.
Good grounds [earths] are critical as others have mentioned.
I always add a good heavy one across one of the insulators [current can't flow across them] as they are called in some manuals, that we know as motor mounts. ADDED: Buy a good Caterpillar 6V high cranking amp Battery [know someone @ a dealer ask them to get one for you with discount] & keep on trickle charge.
 

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So just letting you all know you have helped me out a great deal. I am not a mechanic and rely on my husband (Pender) who has kept this CJ2A running and pretty much original for last 20+ years. Pender is a farmer and therefore has a broad working knowledge of all things and we have a community mechanic (Joe) who worked in the motor pool during Vietnam. But you guys, know all "things" Willys and have enhanced my question asking of Pender and Joe. Have ordered a new wiring harness (do not want to start a fire) for horn mounted on firewall with turn signals from Walck's. Then will be converting to 12 volts battery but keeping anything and everything removed from the jeep. Pender is tired of me saying the jeep won't crank and having to intervene. I am retired and driving the jeep more than my car. I can get to 2 small towns (8 miles) and buy most things I want. I smile all the while I am driving this jeep that I have been driving for 52 of my 63 years. Thank y'all so much for your help...
 
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