So What Happened? - M1009 starter

[ballencd]

Hi, I have a question as to what happened so I can figure out what I should do to have it not happen again.

I have had my 1986 M1009 for 15 years. It has about 250K miles on it and has been running great. It is a backup vehicle so it does not get driven every day but normally once or twice a week. The starter was rebuilt about 11-12 years ago and I have had no problem with it at all. I did replace the flex plate when I rebuilt the starter. Last week I was 22 miles from home and when I hit the starter to go home I got a quick click under the hood and then nothing. The under dash relay clicked but no other sounds. I found lots of pack rat junk (sticks/insulation/leaves/bed) under the hood so I suspected it was a chewed wiring issue but could not find any cut wires. My battery terminals all looked tight. The 24v gauge was a hair over the middle of the yellow which is normal for my vehicle and normally goes up to green when started and revved a bit to get the alternator exciter working. A friendly guy in a pickup stopped and offered help and we tried to jump each battery with his vehicle. We attempted one try on each battery but the gauge did not move up nor did it try to start on either attempt other then the under dash relay clicking. I then had the car towed home (tools and charger are home) and verified the batteries were fully charged....both about 12.6-12.8 volts. I pulled the under dash relay and verified 24v to battery side of relay and attempted to jump the 24v to throw the started solenoid on the starter. What I got was no noise at the starter solenoid but a huge flash and the jumper wire started heating up fast in my hand.....it was a 12ga wire. I then pulled the starter and tested it with 24v with jumper cables on the ground. It tested OK....also tested the starter solenoid and it too was good. Leaving the wires off the starter hanging in the clear (so as to not short anything) I jumped the under dash relay again and got nothing at all.....(i.e. no shorts in the wires to the starter).

What to do.....?? At this point all indications said the starter was good so I put it back in and attempted to start again....just a click as before from the under dash solenoid. I removed the under dash relay again and jumped the 24v wires and the starter worked as it should. Starter working but under dash relay dead at this time.

I am assuming that the starter was stuck in some not normal condition and the dropping it on the ground when removing it unstuck it but I am trying to figure out why the arc and heat when in the stuck position and attempting to jump the under dash relay. The relay obviously got toasted when I first attempted to start it. I assume the click I heard under the hood on that first start was the starter solenoid moving.....??? The arc/heat implies that the starter solenoid coil was not in the loop and I was shorted directly to ground which actually caused the arc and heat.

While out I did pull apart the starter solenoid and clean the contacts but they were not very badly pitted. I also turned the post on the bat+ to get a clean piece of copper for a contact but again it did not look bad enough to cause it to stick. And sticking (in my mind) would not have caused the arc and heat when trying to jump at the under dash solenoid......

I now have a momentary contact switch under the dash in place of the under dash relay (which did get toasted) and the starter is working fine at this point.

Should I go ahead and have the starter rebuilt again just for grins? What are your thoughts on what happened and if anything what should I do now.

Thanks

Charlie

 

[CycleJay]

Dear Sir Charlie,

Yes, it would not be a bad idea to have your starter rebuilt to military standards by a reputable shop, that has been in business a long time.
After all, you said it was last rebuilt 11-12 years ago, so it has been awhile.

Also, in place of the momentary contact switch to start it.

Just do the famous "Doghead starter relay mod", to replace the flawed and sticky
stock starter relay.
I have done that mod myself, and it is the best thing I have done for my M1009,
after I did that, I have never had a problem starting my M1009 since.

If you do that mod, it will make it less likely you will have starting problems with
the charging system, especially less likely to fry any starters you put in your truck.

I hope this helps, good day, good luck, let us all know how it goes.

Just my based on real world facts and experience.

 

[dependable]

It is good to be able to mess with the solenoid as a field repair to get a few more starts, but they are not that serviceable these days, May be worth getting a new one. If you can afford it, buy another starter and the rebuild the old one as a spare.

 

[ballencd]

Thanks for the input guys. I have considered the doghead relay mod several times but have never installed it as I have never had trouble with the relay before this. At this time I think the starter issue (whatever it was) caused the relay to fry vs the relay causing a problem with the starter. Also I have bypassed the glow plug relay card many years ago and have a momentary contact switch under the dash to fire off the glow plugs and kinda like the one I just put next to it for the starter. Less parts is better sometimes. Since I installed the glow plug card bypass I have not had any problems with the glow plugs either and before it I had to replace the glow plugs several times.

I am still trying to figure out what caused the problem and the arc/heat issue when attempting to bypass the under dash relay.

Anyone have any ideas on that issue?

later

Charlie

 

[gungearz]

Good luck and keep us posted on the issue until it gets resolved...

 

[doghead]

I have considered the doghead relay mod several times but have never installed it as I have never had trouble with the relay before this.

Do you have smoke detectors? Has your house ever burned down before?

At this time I think the starter issue (whatever it was) caused the relay to fry vs the relay causing a problem with the starter.

Exactly, this is called cause and effect. The reason you do the DH relay mod is to eliminate the effect(that does collateral damage). The cause is almost always the starter(failure). The stock relay is the weak point that fails when something else causes it to stick(overloading it and it's internal design fails in the on position under an overload).

I am still trying to figure out what caused the problem and the arc/heat issue when attempting to bypass the under dash relay.

Anyone have any ideas on that issue?

You have a bad starter or starter solenoid.

Less parts is better sometimes.

I have a hand crank from a model A ford, you may be able to adapt.

 

[ballencd]

Doghead,

A simple explanation like:

"You should rebuild the starter and also do the DH relay mod. The cause is almost always the starter(failure). The stock relay is the weak point that fails when something else causes it to stick(overloading it and it's internal design fails in the on position under an overload)."

Maybe at that point go into some detail to answer my follow up question about the reason I got a dead short when I tried to jump the under dash relay.

Thanks

Charlie

 

[JGBallew]

I have a hand crank from a model A ford, you may be able to adapt.

Ohh! Hang onto that, I just had to make a crank for a M-37!
One never knows when one will need a good crankin.

 

[JGBallew]

Doghead,

A simple explanation like:

"You should rebuild the starter and also do the DH relay mod. The cause is almost always the starter(failure). The stock relay is the weak point that fails when something else causes it to stick(overloading it and it's internal design fails in the on position under an overload)."

Maybe at that point go into some detail to answer my follow up question about the reason I got a dead short when I tried to jump the under dash relay.

Thanks

Charlie

A bench test with no load, just hitting it with 24 volts and noting that it spins won't tell you if you have a damaged commutator.

Until you can duplicate the "dead short" with a known good starter, your present starter is the likely culprit.

 

[o1951]

#12 wire is too light to handle the amps - would expect it to get hot with a good starter. I use a heavy screwdriver blade, jack handle, piece of copper pipe, or wire larger than #6 if i have it.

I would drop the starter, check for rodent debris/ nest in the bell housing that might have gotten caught in teeth, jamming it up. Check starter pinion gear and ring gear for damage.
Then R & R starter. Lube bushings - they need it after 12 years, check commutator for burned spots, armature and field coils for grounds. Make sure brushes move freely in holders and there is enough brush left.
Should be good to go.

Personally, I like that relay. If there is a fault, with 24 volt system, I want something that does little damage to fail. I do not want any wires to overheat and catch fire.

 

[ballencd]

Thanks JGB,

I will get it bench tested and most likely rebuilt and add the DH mod to protect me in the future.

Charlie

 

[doghead]

Please add your State to your location information. This is a site requirement.

Personally, I like that relay. If there is a fault, with 24 volt system, I want something that does little damage to fail.

I think your misunderstanding what happens when the stock under-dash relay fails.

 

[jeffhuey1n]

Sounds like a cascade failure. Each piece of your starter system is going bad. Individual parts may still work marginally by themselves but when added together with the rest, failure occures. 12+ years since any maintenance was required is quite a record to be proud of. It sounds to me like you need to do a compete start system overhaul so you can get another 12 years out of it. I have seen this type of failure before. Granted it was on helicopters but a 24 volt starter system is basically the same no matter the platform. A little corrosion here, a frayed wire there; add in a weak solenoid and click, no start.

Just my