55 CJ5 Battery Issues - need your help

New member from the Tahoe area here. I should also make it clear that I don't know jack about cars and am hoping to learn. Got the willy this past summer. Replaced the battery and no issues for about 1.5 months, after which the battery would go dead. I would jump it and the car would start right away, but after awhile, it took a LOT of charging for the car to start.

My guess is that something is pulling from the battery (some light research suggests this could be related to the alternator), but I'm not a car guy (at least yet), so any help from this group would be awesome.

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Originally Posted by tahoewilly

Replaced the battery and no issues for about 1.5 months, after which the battery would go dead. I would jump it and the car would start right away, but after awhile, it took a LOT of charging for the car to start.

My guess is that something is pulling from the battery (some light research suggests this could be related to the alternator)

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Well, we try to help.

The 55 CJ5 was originally a 6-volt Jeep, 12-volt conversion was about '57 and that was originally a generator, not an alternator. You have a conversion to a 12-volt alternator system.

As a quick work-around, pull the + battery terminal if you don't want to work on this just now. If the battery goes down with the + cable disconnected, you have a battery problem.

Next, pull the alternator and go have it tested. A defective internal regulator or shorted diode will drain a battery. If you have a good battery and a good alternator - its troubleshooting time.

There is probably no good record of just how the conversion was done, so it may have to go to a shop for someone to poke around and figure it out.

It's hard to troubleshoot a conversion on-line; but ask questions and we'll do our best to help.

There is a similar post for a 56 CJ-3B with a 12-volt conversion, so read his posts as well.

And, get a shop manual. You sat you're not a car guy, but a Shop Manual will help you learn to be a Jeep guy...

Take some pictures of what you have. Some close ups of the regulator, the back of the alternator, and the battery. That will help a lot.

https://willysjeepforum.kaiserwillys...re-in-a-thread

Thanks guys - Got some snow coming this week, but as soon as the storm passes I'll take a few pics. Will also check out that other thread.

I’m Not an expert but if you have a multimeter set it to 20 volts DC, put the leads to each battery terminal and get a reading. Then crank the Jeep and with the engine revved up check it again. Should be around 14 volts if your alternator is working. My post is the one LarrBeard was referring to. My battery was going dead also. The alternator was not charging. I assumed it was bad but after testing and found it was good I had to start troubleshooting. My issue was a bad ground from a gauge to the firewall. Easiest thing to fix but was the last thing I looked at. A multimeter is an invaluable tool to have. Not as intimidating as it may first appear. Good luck!

Thanks for chiming in - looks like I have some troubleshooting ahead of me!

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Originally Posted by Mchambers

... but was the last thing I looked at. A multimeter is an invaluable tool to have. Not as intimidating as it may first appear. Good luck!

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A. We usually end up fixing the last thing we look at. AS my wife once wisely said; "I always find my car keys in the last place I look". I couldn't resist; "There is no telling what else you might find if you just keep looking". Not one of my better choices.

B. Go get a cheap Horrible Frate multimeter. Read the instructions a bit, it's not hard at all. Set up the meter to read current - start on the highest range and work down as needed. Pull the + cable off the battery. Hook the meter in series with the battery and disconnected cable. If you read any current, you have a sneak path somewhere in the vehicle. I'd pull the alternator first since it is one big piece and relatively easy to get to.

(I often end up leaving my heater fan on low - it will eat my battery in about 8 hours...).

Good luck - we're here to "hep' yew"

Does your cluster have just an "Amps" light - no gauge?

I keep getting confused between witch one of these we are writing about! I was on Mchambers post and then I was here and now....

Haha as LarrBeard always says, It is amazing how we always seem to be working on the same things at the same times!

I have a similar issue. My battery will run down over a few days. Now when I shut it off, I take the ground cable off of the battery. I can rub it on the terminal and see the very slightest spark. Everything on it is new with the exception of the ignition switch. When I get time I'm going to check out the switch to see if it is bleeding some current through that switch.

If you have nothing in the circuit like a radio for instance that might have a capacitor in it, the only place I can think of for a significant leak would be in the charging circuit. In an alternator it is usually leaking diodes in the Alternator. In a generator it is usually leakage in the regulator. Leave the battery hooked up and disconnect the power to the Alternator/regulator circuit. Put your multi meter in there on milliamps and see if you have current draw with the charging circuit disconnected.

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Originally Posted by okiemark

I have a similar issue. My battery will run down over a few days. Now when I shut it off, I take the ground cable off of the battery. I can rub it on the terminal and see the very slightest spark. Everything on it is new with the exception of the ignition switch. When I get time I'm going to check out the switch to see if it is bleeding some current through that switch.

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Yep, that little spark is a sure sign of a sneak path load somewhere. The M38 series with the24-volt systems are notorious for developing sneak path discharge issues.

The easiest thing to check first was the alternator so I unhooked it and still a draw. And I mean a draw so small you have to turn out the lights and still barely see it, but enough to run down the battery over a weeks time. In the mean time, I just pull the ground cable off the battery when I'm not using it.

Mark, see if there is a very small amount of voltage at the + on the coil. Like millivolts.

I love that we're all working on the same stuff! Unfortunately, the car is covered in snow (no garage) and I won't be able to dig into to some of these options until it melts/start to warm up. I'll follow up when that happens + when I've tried some of this stuff.

Thank you again to everyone who's reached out - I'm pumped to learn and get my hands dirty, I just wish I had a damn garage.

Patience Grasshopper... the first requirement for a Jeep Project.

Ok folks - winter is over and I've managed to enlist a neighbor who's been helping me trouble shoot a bit. Right now our hypothesis is that the engine might be getting tired. We tested the pressure and it was yielding about 50-60, well below what's needed to fire this thing up. The other issue may be related to the timing gear set.

Here's my question - what's the right sub-group to ask around if anyone is selling an L4 engine and/or a timing gear set that works for a '55 CJ-5?

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Originally Posted by tahoewilly

Ok folks - winter is over and I've managed to enlist a neighbor who's been helping me trouble shoot a bit. Right now our hypothesis is that the engine might be getting tired. We tested the pressure and it was yielding about 50-60, well below what's needed to fire this thing up. The other issue may be related to the timing gear set.

Here's my question - what's the right sub-group to ask around if anyone is selling an L4 engine and/or a timing gear set that works for a '55 CJ-5?

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Just comments:

50 -60 pounds of compression is way too low - is it consistent across all four cylinders? It could be worn rings, valves or a combination of both.

Timing gear stuff is available from Kaiser-Willys.

https://www.kaiserwillys.com/vehicle...h-4-134-engine

You ask about an L4 engine in the same sentence as mentioning a '55 CJ-5. The CJ-5 had an F-134 engine originally.

Checking compression on a stone cold engine is more of a how well it pumps up in a few strokes and consistency between the cylinders. The process outlined in the service manual is the way to check a cold motor. Refer to paragraph C-7 in the Universal Manual for the procedure. Somewhere we discussed this before on this forum. Using only 4 complete strokes to diagnose each cylinder, you are looking for how fast the cylinder pumps up in four strokes and how consistent each cylinder is. There isn't a spec for "cold compression" Until the pistons warm up and "fit" the cylinders, considerable compression is lost. Once warm you can look for the correct psi compression numbers. Since the 134's have less than 7 to 1 compression, 50 to 60 psi on a used cold engine is possible. I think it will fire up if you get 60 psi in 4 strokes on all cylinders, if it comes up quickly. If the first stroke gives you 70% or so of the total psi reading, and the next three strokes bring it up to the highest reading, that is what you are looking for. For the first stroke to give you a good squeeze and the next three bring it right up to a maximum number, at stater cranking speed all spark plugs out.

LarrBeard, Bmorgil - thanks for the help (again). I'm going to tinker a bit further before I pull trigger on any new parts just to make sure I'm not missing anything. Will report back.

Okay - so we tinkered further. Bought a new coil and there's healthy spark so we can eliminate the resistor as the problem. Also re-tested the compression for each of the four cylinders, here were the results of the highest compression both before and after I added a dab of oil: 55 to 75; 60 to 80; 60 to 90, 60 to 100.

We also ruled out that there is a draw on the battery.

In chatting through this with my neighbor, who is actually a car guy, our hypothesis is now that the engine is tired. In other words, do you think the fix here is a new engine block? If so, that's too bad because it likely means I bought a lemon (only bought this last July).

If not any other ideas for what we could eliminate/test for? She's a beaut, but I don't have the time, skills or knowledge for a full engine replace.

Those are good enough to start it on the compression TW. Will it at least fire with a shot of ether? If it wont ignite ether, are you sure there is spark at the plug? You have enough compression to start it with a shot of ether that's for sure. If there is old fuel in it, I have seen gasoline get so bad it will not light with a match. Once everything volatilizes that can evaporate out, there is nothing flammable left. I have seen gas this bad "put the fire out" even with ether. Make sure the carb and tank are drained of any potential bad gas or water. That thing should fire on a shot of ether.

I think if you can get it to fire and warm up, it might just seal up pretty good on the compression. As I said earlier, you cannot rely solely on the compression numbers on a cold engine. The oil helps with the loose fit of a cold piston. It is not yet an indicator of bad rings and/or a worn cylinder.

Put some gas in it! Seriously though, if you have good spark but no fire then it is a fuel problem. Possibly a timing or firing order issue but those tend to fire eventually (sometimes lighting the carb on fire). One with the timing 180 degrees out may not fire. I haven’t seen that on these engines but I broke a starter on a different engine that fired 180 out. It had to be cranked a lot before it fired.

As you are pointing out, it is important to verify the facts. You need to check and verify spark at the correct time. If there is compression, fuel and spark at the correct time, it will fire. If you are sure of the spark, you have verified some fair compression, and you squirt in some ether, it will fire. If it fires but won't keep running, the search is on for the fuel issue. Keep on it, you'll get it going! Going back to the basics on these is the way to go.