M818/Cummins Starting Problem

[GI-JOE]

Hi everyone,
I have a bobbed M818 with the NHC250 that I think is having starter problems. The truck had been sitting for about 4 months while I was recovering from surgery. When I was strong enough to drive it again I went to where the truck is stored, connected the batterys, and it fired right up. I drove the truck for about 20 miles then shut it off for about 20 minutes. When I went to start it again it turned over kinda slow but the truck still started right up. I drove the truck 10 miles to a fuel station and shut the truck off to wait my turn.When it was time to move up to the pump I hit the switch, heard a loud click, then nothing. I gave things a quick look over but could see nothing amiss. I called a tow truck for a bump. the added voltage (24) didn't seem to help at all. The tow truck driver volunteered to give me a tug so I turned the screw on top of the pump, swiched power on, and before the tow truck had moved 3 feet I was running again. The tow truck driver followed me to where I store the truck and the truck ran perfectly on the way back. after I parked the truck I tried the starter again, just got a click.
I pulled the batteries and they checked out fine. I started working from the batteries inward, cleaning cable ends and terminals as I went. Everything looks pretty clean. I checked the cables and terminals at the starter and everything looks clean.
The only two pieces of advise I heard are to wack the starter with a mallet to try and free up the brushes if they're stuck and add an additional ground cable from the starter motor to the engine block.
I do have a spare starter that I've had checked out and it seems good to go.
Any advise as to other things I can check before I throw another starter at this thing? Any advice would be appreciated.
Thanks

 

[Hooty481]

have someone smack it with a hammer while your are trying to start it. then if no good change starter. it could be a solenoid problem more than likely it would be the starter.

 

[papercu]

I would make sure batteries are fully charged (are they Hawkers?) if they are charged, recheck connections. Wayne

 

[swbradley1]

I have a similar problem on another diesel and the whacking with something on the starter usually works. Indicates a sticky solenoid.

 

[rrrr]

Sticky solenoid or a dead spot on the armature of the starter.

 

[jwaller]

could also be the relay box. I'd bet thats your issue. test the starter with a manual trigger, if it works fine then your issue is the box.

 

[area52]

search for protective control box on here, it has some relays for the starting system and they can go bad.

 

[73m819]

Could be the once PROUD, now HUMBLED 818 is fighting back, now that it is only a PATHETIC 81

 

[MWMULES]

Just had same with my 818, first was bad cable, low air alarm on, switched to run and clunk. It turned out one of the cables had corroded inside of the lug, looked good on the outside but as I was checking all cables and cleaning them the lug as I twisted it came off in my hand. Got a new cable made and worked fine. Then earlier this month had same problem cables all good, I pulled all 4 batteries and charged them all read 12+ volts, put back in and clunk! Had a buddy show up and asked if I check load??? He had a load tester turned out all showed good volts but only held 8 to 16%, put 2 new in and hot straight & normal. 2 days later some #&*($@$ stole the dead ones on the ground and the new ones I had just put in!

 

[GI-JOE]

Aw Geez here we go!
I knew at least ONE guy would bust my chops for bobbing this truck. I think the truck has been very happy. It's retired and knows it will never have to lug the loads it once did. On sunny days it get to participate in car shows instead of take bullets. It's lost a bunch of flab it no longer needs and now goes down the road at 70mph and cuts thru parking lots like a sports car!
Seriously, I'm jealous of you guys that have entire heards of the big stuff. My little "pick-up" is about the max for me at this point in my life. I'm not dead yet. I'd love to have a wrecker.
My terminals all looked good. I'd had similar experience to MW so I alwsy twist the cables at the lugs to see if they're up to snuff. I'll check the relay box this weekend. I had my bat's load lested and they're in fine shape. I'm just running 2x 12v RV batteries but they've spun this truck over in below 20 degree temp with no prob. Keep the ideas coming and I'l let everyone know what the verdict is. Its snowing in the Willamette Valley and I want to take this thing out to play. I've been dying to try on my new cold-front.
Blake

 

[73m819]

I run two big 8Ds, one in each battery boxes

70 is a bit fast, loose brakes could be a bad day, blowing a steer tire is a seat clencher