[scottduke83]

Hey everyone.
I bought a used LT155, ran once and then afterwards, when you turn the ignition, the solenoid would hum.
I checked the voltage.
The battery is getting 12 volts, the line from the battery to the solenoid is getting 12 volts but the line from the solenoid to the starter is only getting 8 volts.
Its a 4 pole solenoid so it has a purple line going out and a black ground going out as well.
Does anyone know if this is a ground issue or what it might be?
All posts and terminals are cleaned and tested except for the black ground because i dont know how to test that.
Any help would be appreciated.

 

[cablenewsguy]

Any power from a known good 12v location on your tractor should tell you if your ground is good. You could try adding another ground strap just to rule things out.

 

[rayjay]

As was mentioned, adding a jumper wire with an alligator clip on each end from the engine block to the ground terminal on the solenoid would quickly tell you if the solenoid was bad. The ground terminal on the solenoid is wired to various safety switches so adding a temporary jumper bypasses the safety switches for troubleshooting purposes. If the solenoid starts working then you know to investigate the safety switches and their wiring. If the solenoid still doesn't work double check the continuity of the jumper wire and if it's good then replace the solenoid.

 

[rayjay]

Actually, after re-reading your post the solenoid must have problems. If you are able to get 8V at the starter terminal then the solenoid is engaging so the ground wire is doing it's thing. I would still try the temp jumper but it sounds like your solenoid is bad. You should also take a close look at the negative wire going from the batt to the engine block and frame.

 

[scottduke83]

How do i test the negative ground from the battery?

 

[jtclays]

Since it ran once, I'd be looking at engine mounts or negative ground hookups like ray said. These can be loosey goosey and cause all kinds of issues. I'm betting what ray said, he knows his stuff:fing32:

 

[rayjay]

Mostly just make sure you have a negative wire bolted to the engine the same size as the positive wire that goes to the solenoid. If the negative wire is bolted to the frame you could have a poor ground to the engine block resulting in low voltage to the starter. Make sure the engine block is clean bare metal where the negative wire is bolted. Corrosion could also cause issues.

 

[scottduke83]

I actually bought a new solenoid because it was only $13 and i was having the exact same results.
the negative terminal on the solenoid is very very small.
But if i hook a negative ground to that and directly to the battery, should i get 12 volts out of the solenoid-starter terminal?

 

[rayjay]

I bet that if you hook your voltmeter directly to the battery and turn the key to start you get the same 8v. Most likely your battery is shot unless it's very new.

 

[scottduke83]

The battery is brand new too.
I tested it and it is pushing 12 volts also.

 

[rayjay]

Could be a bad starter. Can you turn the motor by hand or with the bolt on the bottom of the PTO pulley ? Just want to make sure the cylinder isn't full of gas hydro locking the motor.

Good luck.

 

[scottduke83]

I can turn the motor by hand.
I tried jumping straight to the starter today and didnt get any response from the starter at all.
No clicking or anything.
I had a different 12v battery, hooked up positive and negative to the battery, grounded it on the motor and put the other positive to the positive post on the starter.
So it seems like it might be a bad starter but it seems weird that i would be getting nothing from it, no clicks or hums or anything.