New and in search of info

Hello all,

Yep, I am the new dude and am posting to seek some help. I picked up a 44 MB that had "battery issues", bottom line up front is something is killing the battery as it sits and I lack the ability to find the bad connection or wire that is shorting it out. I've gone through 3 6V batteries in 2 years and even with a full charge/ new battery getting it started is an act of faith. Some days it turns over right away, some it won't start at all, at best when it won't crank the starter turns the engine maybe 1/2 to 1/3 or a full rotation. I've tried adding grounding cables to the frame and from the starter to the block and the back to the frame but it changes nothing. I'll see if I can post a video with what it does, hoping to solve the root cause as when it runs it is a complete blast to drive around.

Nathanael

Welcome Nethanel! A '44 MB is a great find, especially in running condition! The wiring system is fairly simple on the early Jeeps, all the way through to the early CJ5s, but a parasitic drain can drive one to drink. The first order of business would be to look at the starter itself. I would be willing to bet that there would be high resistance in the starter motor. This would cause the symptoms that you are describing, and may have you thinking that there were not enough grounding to the frame. The starter is a simple motor, but the bearings do wear out. Also the windings may be glazed over, and causing the high resistance. An easy test would be to take a multi meter and measure across the negative battery terminal to the positive cable at the starter, then have a helper try and start the engine. The voltage drop should not drop bellow 4 volts on a 6 volt system. If you have less than 4 volts, then you have your source of issue.

If the starter checks out, then you can start checking out the buss bar on the driver's side inner fender. Disconnect one circuit at a time, and check for a voltage draw on each. Another common source of draw would be to check the headlight switch.

Keep us in the loop on what you are seeing, or if you have any questions.

I would not discount that there are two issues:

A. If the battery is dead after sitting a while, I vote for the parasitic drain problem..

B. One-third to one half turn on the starter is generally a brush, commutator or bearing issue. Find an Auto electric shop with an old guy still there. NAPA and Auto Zone won't recognize a 6-volt Jeep starter.

And, let us know what you find. Your answer will help about another dozen folks who are reading the notes here.

During rewiring I found a faulty brake light switch on my CJ2a. It had failed slightly "on" so the brake light was continually on dim/flicker.

gmwillys, this is perfect and thank you. I plan on working the issue over the weekend and will post back, thanks again.

Larboard, as above thanks for the words, hopefully I can get this sorted out pretty quickly and get the Jeep back on the road to enjoy it.

Yet another question, tonight while still trouble shooting my Jeep a friend of mine noticed that when he tested the connection from the positive wire on the starter to the frame mounted ground and it showed a closed circuit. My limited electronic knowledge says it might be a positively ground vehicle. Again my knowledge is limited, the question is, if it were reversed polarity would the started still spin the correct direction?? Its started in the past but only maybe once every 50 times I've tried, 3 batteries in 12 months (which the closed circuit explains) but like gmwillys stated above this is driving me to drink!! Thanks in advance.

Nathanael

Quote:

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Originally Posted by nkarrs

the connection from the positive wire on the starter to the frame mounted ground and it showed a closed circuit. Nathanael

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This is normal. What you are seeing here are the internal field and armature windings of the starter. All Jeeps are negative ground vehicles.

Ahhh, thanks. This thing is driving me nuts.

Quote:

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Originally Posted by nkarrs

Ahhh, thanks. This thing is driving me nuts.

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Yeah, we've all been nuts at one time or another. Some of us are stuck there.

Do you have a multimeter? If not, go to Harbor Freight and get one of the cheap ones. Their cheap 7-function meter has a 10 Amp DC scale. Read the book or find a friend who knows how to set up the meter to measure DC Amps on the 10 Amp scale. Turn off all of the electrical stuff in the vehicle. Lift the positive terminal clamp off the battery. Connect up the meter to read DC Amps from the positive terminal of the battery to the clamp you removed. With all of the electrical stuff OFF, you should read no current being drawn from the battery - the meter should read 0.00X.

If it doesn't, you have a parasitic drain. Start disconnecting things. This is a tedious task - but there is no easy way. I'm not sure you don't have a starter issue if it still only cranks the engine a half turn or so with a good battery.

Troubleshooting by email is hard. but we'll hang in there with you.

https://youtu.be/96WytPHhAV4

For those in the thread, this is the issue I am dealing with, besides a short that is continually slow draining my battery, this is the sound the Jeep makes when trying to start up. The starter engages then stops after about 1/4 to 1/3 of a rotation, some days it does this until the batt is dead, some days it fires right up.

Still going to keep at it!!