m151a2 will not turn over or power on

This is the place to get help with technical matters concerning your M151 jeep

Moderators: rickf, raymond, Mr. Recovery

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

m151a2 will not turn over or power on

Unread post by tbh726 » June 20th, 2021, 7:44 pm

All need some help, I have a m151a2 that was sitting for the last 16 years in a garage, it was working fine i am told when they pulled it into the garage. it was my brother so i am guessing that is correct. I put in new batteries and wired everything back with the batteries. i get 24 volts from the batteries i also get 24 volts at the plug up by the hood, i think it was where they were connected if you were jumping another 24 volts system.

keep in mind i rode in them when in the military, but never drove one, so it could be me just not knowing.

when i flip the switch to on i see nothing. lights do not come on, heater fan has no power, wipers nope, voltage regulator nothing. Needless to say it will not turn over either.

Does anyone have any ideas what to check from this point?

thanks

tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » June 20th, 2021, 9:26 pm

The wire you are looking for is the #5 wire and it hooks into the system at the foot starter switch. This is where the ignition switch gets power from. You need to look over the wiring very closely to make sure it is all intact before doing to much since these are known for the wiring breaking down and shorting out. And next thing is I am guessing you want to just hit the switch and see if it starts? Have you pulled the plugs and squirted oil in the cylinders? Also have you taken the valve cover off and rotated the engine at least two full rotations by hand to make sure you do not have any stuck valves? An engine sitting that long needs to be pre oiled and checked over before trying to start it. Just because it ran 16 years ago means nothing. The engine and transmission could be full of water from condensation. Differentials also need to be checked for condensation by draining and refilling.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

kmam
Sergeant Major
Sergeant Major
Posts: 524
Joined: June 6th, 2015, 7:39 am
Location: Kuranda, Far North Queensland, Australia

Re: m151a2 will not turn over or power on

Unread post by kmam » June 20th, 2021, 9:50 pm

Ah, Rick, you are so quick on the trigger. I was starting to write a reply when yours came up.

Just one thing, when you do the checks, if the voltages are OK and you are connecting your meter directly to the battery negative terminal I would suspect the connection from battery to the vehicle frame. Perhaps the easiest thing to do as step 1 would be to disconnect that and clean the body at the connection point and ensure the lead, etc are free from rust. Then bolt it back and see if things are now working.

After checking the voltage on 5 as Rick says, if it is OK I would check the output from the circuit breakers. Probably the easiest way is to turn on the ignition switch and then check that you have 24V on wire 27. You can get to that by taking off the instrument panel and it connects to all the gauges. 27 also goes to the wiper motor where is is labelled as 71. If you are not getting 24V at 5, then that is the problem. If you are and not getting it at 27, it is your circuit breaker(s). If you are getting at 27 and there is no voltage at the instruments I would be looking at the earth connection from the battery.

For the electrics, it is just a matter of moving a step at a time. Having a circuit diagram may help but it can also confuse you...

Good luck
Howard

Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » June 20th, 2021, 10:45 pm

thanks guys,

yes i was not planning on starting the engine, i have the gas tank out, my thought was if i could get the motor to turn over it would get some oil up in the valve covers did not think about turning it manually first.. was planning on pulling the plugs and shooting a couple squirts of 10-30 into each cylinder. before i plan to drive i was going to drain all fluids and replace them first. i am glad based on your replies i was not too far off on that.

What is concerning me was i can not even get the brake lights, head lights, blinkers, wipers or heater fan to even turn on... a breaker popped would do that, but not sure if the #5 wire would cause that... where are the circuit breakers located at? hoping i dont have to replace all of the wiring harness..

i did figure everything rubber would need to be changed. hoses, brake lines, vacuum lines, fuel pump, fuel lines ect... not sure on what else.

your thoughts...

tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » June 21st, 2021, 9:50 am

There is no separate breaker for the lights, they are hot all the time. The breaker for the lights is in the switch. But if you have no power anywhere then be sure to clean the ground from the battery to the body as Howard suggested. I don't know where this was stored but if there is evidence of mice then you have to go over all the wiring. The only breaker involved in this is on the #27 wire and it only controls the gauges. And the #25 breaker which is the horn. When you turn the switch on the ignition should be hot, no breakers inline on that circuit.

As far as top end lube for starting I always like to pour a little Marvel Mystery oil over the rocker shaft and the valves before cranking. This gets oil on the moving parts up top before you even start moving things. 10W-30 in the cylinders is good, it will lubricate and help with initial compression. Check your coolant and oil, best to change the oil before even cranking since if there is condensation in the pan it will be at the bottom and it will be the first thing the oil pump sucks up. Drain it and put fresh oil in. That way you know ahead of time what was in there. If a bunch of water comes out before the oil you might as well pull the powerpak and drop the pan and see what it looks like, I will bet the cylinders will be pretty rusty along with everything else.
Where is this vehicle located? Location has a lot to do with how much of an issue you will have with condensation.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » June 21st, 2021, 4:50 pm

Hi Rick,

it is located in MO, and yes he did have mice in the garage. It sounds like i need to check all of the wiring over. On the Mystery oil i have seen it in stores but never used it. would you recommend doing that after i drain all the engine oil? i am guessing my first priority is the electrical. but if i can drain oil and let the mystery oil sit there to coat the valves and lifters then i can do that first.

tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » June 21st, 2021, 10:15 pm

Yes, drain the oil and put in new 15W-40 Rotella or similar diesel motor oil. The diesel oils still have some of the chemicals that regular oils have lost due to emission rules. Modern gasoline engines no longer use flat tappets so they do not need zinc in the oil anymore. Get yourself a Wix 51515 and put in 4.5 quarts of oil and dump half a quart of the Marvel on the top of the engine. Then disconnect the batteries and pull the starter switch out of the floor and remove the connections, clean and replace. That is where the power from the batteries goes into the system and since it is hidden under the floor they may have never been looked at. You say someone else had "Looked at it". No telling what was done by them either. That starter switch will have the battery cable coming to one side of it and the other side will have the starter wire and the smaller power wire with a #5 tag on it. Make sure they are in the right positions.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » June 23rd, 2021, 10:22 am

Hi Rick,

I went over as much of the wiring system that i could. behind the gauges there were 3 gauge wires that were chewed on. However nothing else showed any chewing or dry rot. I did happen to pull the starter, unfortunately i did not see your post to unscrew and clean up everything. i did try and test the voltage on the #5 wire and like you stated, I figured the system must be getting all power from this point.

I could not get any voltage from #5, my guess is i should. should i expect power at the switch? I would think so. so correct me if i am wrong, I have power (25 volts) to the jumper cable port outside next to the hood, but nothing on the #5 wire that connects to the starter switch. I scratched into the connectors, but no voltage. i have to assume that the positive wire #5 is connected to the jumper port also, this is why i figure i should have power is that correct? if it should, how do i get to that connection where the #5 would connect to the jumper port?



tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » June 23rd, 2021, 1:11 pm

The only thing that slave cable port is hooked to is the batteries, nothing else. Unless bubba has played with it there should not be any other wires hooked to that connection either. The #5 wire that supplies the power to the vehicle is hooked to the starter switch under the floor. I have mentioned this several times. PM me your e-mail address and I will send you a wiring diagram that shows all the connections you need. The #5 wire goes into the ignition switch but the number is changed to #11. If you want to pull the switch and see if you have power at #11 that will tell you if you have power coming in from #5 but I can tell you that if you have no lights then the chances are pretty good that the problem lies either at the starter switch connections or at the battery connections. You have to remember that DC power depends on a complete circuit of power from the battery and back to the battery. So if a ground wire is not connected or if it is dirty it will give you this issue. Rust on the main ground wire is the most common problem in all automotive electrical no start, no crank issues.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » June 25th, 2021, 10:46 pm

Rick

Thanks a bunch, yes you were correct it was at the batteries. It was a little me, a little bubba and a little Government manuals on the m151... When i got the jeep, none of the cables were on any batteries. I had one manual that just showed one cable for Pos and one it appeared for Neg. That is where i messed up one had Pos on the cable the other nothing and i assumed it was Neg. I was able to trace finally the wire from the starter switch to the battery container and realized i had it connected to Neg. After looking for where the Negative wire might be and not finding anything in any manual, i was able to find something in the forum here that i am missing the whole negative wire and it should be mounted in the battery compartment.

Now moving on to your directions on the oil.

Thanks again, i was able to learn a great deal on this, i was able to also see that mice did get to some of the gauge's wiring, but i feel much better on the condition of the wiring.

thanks tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » June 26th, 2021, 9:27 am

The very first rule of diagnosis is to start at the beginning and methodically work your way through to the end. Do not jump around on the process or you will be chasing your tail forever and you will miss simple things. As you have found out. The military manuals are written so that just about any person off the street with almost no knowledge of the workings of a vehicle can fix it. Within reason, I am not talking engine rebuilds here. But the basic stuff is laid out in a format that walks you through each and every step in the order you NEED to take to find the problem. It does work. I will be the first to admit that I simply do not follow the manual because it is very boring BUT! To someone who has no idea how to do this stuff it WILL show you the right way to diagnose a problem. Even though I say I do not follow the manual all of my methods of diagnosis are based on that principal. Start to finish and do not jump around. I have had people on the forums start doing what I ask to diagnose a problem and then they will try something someone else told them to do right in the middle and that simply takes the whole thing back to square one. Start over. I will do that one time and after that I tell them they are on their own, I simply do not have time to keep doing the same thing over and over.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » July 19th, 2021, 9:17 pm

So i was able to get the motor to turn over from the starter switch, engine sounds super smooth turning it over from just starter. working on the fuel lines now, they had been cut and spliced with rubber hose that was rotten so i am replacing them and getting ready to put the gas tank back in(had it cleaned and sealed) then i plan to try and see if i can get it started. I thought i would check the distributor after reading a bunch in here on them and the coils. i seem to have what someone said here a swiss electronic ignition, of a choice between points, prestone or swiss it is the best to have is that correct? a couple other questions; do i have one of the cheap Chinese coils if you can tell by the picture. it seems everyone talks about having spare parts. what should i look for and have on hand.. for the really hard part and i will be looking at manuals tonight, but i have heard and read to check ohms and voltage on the coil or distributer, i have no idea how to do that. do i put the volt meter on the 2 nuts on the coil? should there be volts there all the time? only when cranking the engine? how do i check for ohms? getting into the coil and checking that is all new to me. Do you see anything wrong in the pictures? i have found a few Bubba type things that i have had to fix. a lot of questions i know, but you read the forums and start to wonder and i plan to drive this for sometime.

thanks tim
You do not have the required permissions to view the files attached to this post.

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: m151a2 will not turn over or power on

Unread post by Hambone » July 20th, 2021, 8:54 am


tbh726
Sergeant
Sergeant
Posts: 70
Joined: January 25th, 2021, 12:01 am

Re: m151a2 will not turn over or power on

Unread post by tbh726 » July 20th, 2021, 10:35 am

that is exactly what i was looking for, thanks for that will test the ohms tonight, i do not have the probe he was using for voltage, but i can at least see if i am getting spark... So one thing i got from that is that the non-NOS ones are junk. So where do you find any of the NOS ones? i searched for a while and only found one used one that "tested" good for $100. It sounds like you would want to have an extra coil on hand. do people have the Chinese ones as backups?

thanks
tim

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: m151a2 will not turn over or power on

Unread post by rickf » July 20th, 2021, 10:45 am

I keep several of the Chinese ones as backups. Supposedly the newer ones are not as bad as the old ones. If you can find a NOS coil expect to pay several hundred bucks for it but keep in mind it will be at least 40 years old. New is one thing, 40 year old new is something else, especially when it comes to electrical items. It appears you have an original USA Swiss controls unit so as long as it is good it will serve you for a very long time. Just do not leave the switch on with the engine off. That will wipe out both the coil and the module.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Post Reply