d4h not starting voltage question

[Mikew99]

Ok ive got a cat d4h ran it for a few hours the other day turned it off to make a phone call and wouldn't start back. The story will start in the morning started up great with below freezing temps took off with out checking the fuel got a couple hundred yards and ran out of fuel. Got fuel and filled it up I think I may have cranked it a little too much trying to get it primed and got the starter a little hot but it started up and ran and like i said dozed a few hours with it and turned it off. hit the key switch and just a click tried tapping on the starter no luck tried holding the key on start a few seconds and heard a pop checked batteries and one of the terminals had melted where it attached to the cable replaced two of those still no luck you could hear the Bendix click and nothing else the crank wouldn't even begin to move Put two chargers on the batteries from a generator and went to town got two more terminals and replaced the other two so all new connections at the battery chargers said 100% charged took volt meter and checked had 25.5 volts on starter lead when you hit the key switch it would go to 5.5v took starter off and hooked a 12v jump pack to it and jumped solenoid and bendix engaged and starter turned over with considerable torque put the starter back on dozer and now it will turn the motor over very slowly but volts still read around 5.5v with the key to start at the starter cable any ideas on what is causing this do you think the starter when bad from the cranking? The batteries have been in the dozer for well over a month sitting in the woods turn the master switch on and it turns over great

 

[JD955SC]

Fried starter and possibly damaged cables. You gotta be careful with start attempts like that not to fry the starter (trying to start it with weak batteries can result in the same issues)

keep in mind the starter is putting a lot of strain on the electrical system it’s only supposed to see a very brief use.

 

[Bluox]

If you are using the battery clamps that bolt to the cables throw those away and have someone crimp on a new set of clamps.
Bob

 

[Dave Neubert]

I agree with Bluox if you have those clamp on terminals junk them also try bipassing your master switch

 

[Delmer]

You obviously know how to do a voltage test under load, that's 99% of the way to your answer. Test each cable under load. That is, test from the 24V Positive to the starter, then the cable connecting the batteries, then the ground cable, and the 24v negative battery terminal to the starter case. Across each battery too, in case one or both are shot.

Those numbers will tell you what you have for voltage drops. And you can go from there.

If you have those bolt on battery clamps, you should be able to get it going, but they're junk and won't last.

 

[Bluox]

While you are fixing battery cables pull the mag switch/solenoid off the starter and take the plate with the cable terminals off the switch and see how bad the contacts and plate are burned.
Bob

 

[Mikew99]

thanks for the reply's yep the starter was bad had it rebuilt and starts like a charm did end up buying a cable clamp crimper to do the ends good note is all the dirt is off of the top of the transmission from tracing cables lol

 

[Willie B]

My Dresser got a good going over. New cables, new battery, new master switch. The starter went off to the starter shop for a rebuild. It still started hard! I often had to take the batteries out, take them home & charge them.
Finally one very cold day I needed it. Voltage at the starter was low. I started dismantling the tractor to find the fault. It was the last place I looked. In my case a terminal where the master switch isolates battery negative from ground, then a short cable to a ground on the frame. Sure enough, it had been ground shiny, a new terminal, cable & bolt. The nut hadn't been tightened.

I know just what happened. My son's phone rang, he got distracted.