John Deere 510C Backhoe starter and solenoid

Hello, I have a backhoe(John Deere 510C) sitting on my property I need to move, but am having some trouble with the starter. It's not my backhoe, just storing it for a neighbor down the road that seems to have forgotten about it. I bought a new solenoid to install, put it on the starter and installed them in the backhoe. I can get the starter to spin when I push in the starter button, but the solenoid isn't kicking in the bendex gear. Is there a way to bench test the solenoid? The way the solenoid wiring was hooked up was (see photo) There was the positive cable from the battery and another smaller wire from the battery hooked up to terminal "B" . Wire "A" goes from the solenoid to a post on the side of the starter body. Terminal "C" has a white wire that comes from the harness, which I would assume would be the starter button. The wiring in the machine is quite a mess of splices and taped off contacts, but the starter was working at one point. Terminal "C" also has a copper strap that goes to the starter field post. Can't seem to get the magnet to kick in. I am not good at electrical problems and would appreciate anyone's help to get this thing working. I want to move it away from my building.

If I am looking at it correctly...terminal A would go to the starter button wiring...terminal B would go to the lug with the strap to the starter..terminal C would be the battery cable and 12V feed for the harness

Nope. "Start" wire goes to the little terminal "A", along with the black wire that is already there.

Battery cable and power wire to electrical system connect to "B".

Terminal C connects to the buss bar to the starter. The little screw in that terminal stud he now has a wire attached to is simply to hold the plastic anti-jump starting cover in place, and keep blems from running over themselves and NOT there to have a wire attached to it.

I think the short wire that's attaches to "S" terminal on solenoid marked "A" is suppose to also attach to a starter relay(parts key #15A or 15B) depending on machine SN. Relay has to engage for starter solenoid to engage when using ign switch to activate.


If starter spins but doesn't engage using ign switch then something is wrong with starter gear engagement fork in starter.

"A" is the exciter wire for the solenoid "engage" coil. The solenoid is designed so it will not connect the battery to the starter (via the two big posts) until the plunger is pulled in. So, if you've got power - it means the plunger has moved like it should to engage the starter drive. Sounds like it's not connected mechanically or the drive has a broken clutch.

Since I have the solenoid out, shouldn't I be able to hook up power and check to see if the magnet opens and closes off the starter?

Yes if you complete 12 volt circuit you should be able to bench test it.

I am thinking that the plunger is not engaged with the fork

The plunger is engaged, and it moves freely. I hooked it up to a battery on the bench and also did I test where I jumped it from a running truck. Also, gave power to the solenoid off of the starter. The plunger does not move. My conclusion is bad solenoid. Thanks for all the help. Going to get another solenoid.