M1088A1 Isnt Turning Over, Just A Click When Button Pushed

[ACUF]

Hi Everyone,

Im new to this forum, and new to LMTV, namely a 2001 M1088A1 (Refreshed in 2004). We havent had much of an opportunity to use it as we have been in the process of mounting a knuckle boom. I start the truck fairly regularly, just to let the air system equalize the tire pressures, build operating pressure, and release the air brakes. The last time I started it, (about two weeks ago) it seemed like the batteries were low, and it just barely cranked enough to start, but it did. After letting it run for a little bit, I shut it off, but realized i might have had low batteries and should have let it run a little longer, to refresh the charge etc. Needless to say, when I went to restart it, it just clicked, like it was just a dead battery.

Fast forward to the past week, I have tried numerous things, including jumping from the 12v side for a boost (which I had done a couple times in the past), but no change in its behavior, just a click when starter button is pushed. I did load tests on the batteries, and the two batteries closest to the outside of batt box were low, so i took them out and charged them today, and put them back in after seeing their load testing / voltage where they need to be, to no avail. Just clicking when starter button is pushed..

I have been digging and have seen a number of threads but im still getting different symptoms, ie not even turning over, etc. Tonight I also tried to jump accoss the solinoid on the chassis just behind the starter, but it was dark, although i think it made contact (via a spark) , I didnt hear the starter spin. Anyway, I can keep searching but any suggestions are greatly appreciated! Take care and happy holidays!

Sincerely,

ACUF

 

[coachgeo]

.....
Sincerely,

ACUF

hmmmm........ ACUF .... you had/have a Mog?

 

[fuzzytoaster]

Check the following:
-PDP relays (clean, swap, etc)
-Check individual battery voltages and connections
-Check the starter button itself (they can develop dead spots)
-Check starter cables
-Use a screwdriver to connect the starter remote solenoid prongs (next to the power steering reservoir) with the dash power switch on
-If still no crank replace that solenoid and continue checking for voltage

 

[Ronmar]

exactly what is going click? Start Relay in the power panel, aux start relay on the drivers frame rail, Starter solenoid, all of the above?

what are the 12 and 24 volt test points in the power panel measuring WHILE you are pressing the start button?

 

[ACUF]

Check the following:
-PDP relays (clean, swap, etc)
-Check individual battery voltages and connections
-Check the starter button itself (they can develop dead spots)
-Check starter cables
-Use a screwdriver to connect the starter remote solenoid prongs (next to the power steering reservoir) with the dash power switch on
-If still no crank replace that solenoid and continue checking for voltage

Will do, Thank you!

 

[ACUF]

exactly what is going click? Start Relay in the power panel, aux start relay on the drivers frame rail, Starter solenoid, all of the above?

what are the 12 and 24 volt test points in the power panel measuring WHILE you are pressing the start button?

Thanks for the response, I hear a click when pushing starter button 1. in cab passenger fuse/relay panel (PDP?), 2. solenoid on frame rail, and 3. hear the starter click , just no spin, or crank etc) ie power is going to the starter

 

[ACUF]

hmmmm........ ACUF .... you had/have a Mog?

Hey Geo, yep, I sent you a text, must be an old number. Are you still in the area?

 

[coachgeo]

Hey Geo, yep, I sent you a text, must be an old number. Are you still in the area?

yes; still in area
I'll check my text. I'll pm you my number

 

[Ronmar]

Thanks for the response, I hear a click when pushing starter button 1. in cab passenger fuse/relay panel (PDP?), 2. solenoid on frame rail, and 3. hear the starter click , just no spin, or crank etc) ie power is going to the starter

Well thats easy. If those 3 are clicking the start circuit sounds OK. Sounds like you may have an internal short in the starter since you got a spark shorting the starter terminals on the solenoid with no spin. What does the 24v at the battery do when you try to start it.

I would say you probably need to pull the starter and take it apart, clean and inspect. Often what happens is brush dust collects where it shouldn’t and shorts the input to the case...

 

[ACUF]

Well thats easy. If those 3 are clicking the start circuit sounds OK. Sounds like you may have an internal short in the starter since you got a spark shorting the starter terminals on the solenoid with no spin. What does the 24v at the battery do when you try to start it.

I would say you probably need to pull the starter and take it apart, clean and inspect. Often what happens is brush dust collects where it shouldn’t and shorts the input to the case...

Thanks for the follow up! Im heading over there in the next hour and will see if I can somehow test the 24v side of the batteries, but I wont have any help today.. The first thing, and probable the most obvious should have been the old tapping the starter with a hammer, which I should have tried first to begin with

 

[Ronmar]

Thanks for the follow up! Im heading over there in the next hour and will see if I can somehow test the 24v side of the batteries, but I wont have any help today.. The first thing, and probable the most obvious should have been the old tapping the starter with a hammer, which I should have tried first to begin with

Yep, tapping may re-distribute the carbon or otherwise restore the current pathway thru the motor windings. But that has only been a tmep fix in my experience and the starter still needs to be pulled and inspected, cleaned and bushings lubed.

I guess you should also try and barr the engine over by hand to make sure it isn’t seized. The procedure to do this involves a socket on the ALTERNATOR pulley nut and you should be able to see the crank rotate(may need to push on the alt belts to add some extra tension/traction).

if the batteries are OK, with a shorted starter I would expect the 28V to dip down into the 17-18V range just like it does with a start. If that voltage completely disappears or does not significantly change then you have a battery opening under load or the circuit is opening under load respectively.

 

[frank8003]

charging system fault batteries dead

 

[coachgeo]

charging system fault batteries dead

good news. according to ACUF...... it started. Just a few taps on the starter and she spun fast enough to fire her up.

 

[ACUF]

good news. according to ACUF...... it started. Just a few taps on the starter and she spun fast enough to fire her up.

Yes, sad to say it was just that simple, but im relieved! In my own intimidation of new machinery, I assumed the worst like a dead starter or major electrical fault, and I should have began from square one, tapping the starter to wake it up.. Funny I was reading another thread of a similar, (newer generation stewart stevenson) that had the exact same problems, and all it needed was a little sweet talking with the baby sledge Thank you for the responses!

As far as that goes, I hope to get a build thread going with some pics of our knuckle boom project. In the meantime, heres a preview pic. Happy Holidays

 

[Ronmar]

Yes, sad to say it was just that simple, but im relieved! In my own intimidation of new machinery, I assumed the worst like a dead starter or major electrical fault, and I should have began from square one, tapping the starter to wake it up.. Funny I was reading another thread of a similar, (newer generation stewart stevenson) that had the exact same problems, and all it needed was a little sweet talking with the baby sledge Thank you for the responses!

As far as that goes, I hope to get a build thread going with some pics of our knuckle boom project. In the meantime, heres a preview pic. Happy Holidays

Cool! The having to tap has always been a prelude to a complete failure in my experience. I would pull it and clean it out and re-lube it. You need a support strap/hoist to get this one in and out, but the starters themselves are not hard to work on...

 

[Mullaney]

Yes, sad to say it was just that simple, but im relieved! In my own intimidation of new machinery, I assumed the worst like a dead starter or major electrical fault, and I should have began from square one, tapping the starter to wake it up.. Funny I was reading another thread of a similar, (newer generation stewart stevenson) that had the exact same problems, and all it needed was a little sweet talking with the baby sledge Thank you for the responses!

As far as that goes, I hope to get a build thread going with some pics of our knuckle boom project. In the meantime, heres a preview pic. Happy Holidays

That orange boom is really ugly on the back of your truck... You should unbolt it, then call me and I will run by and pick it up and get it out of your way

.