PT-425 PTO Not Starting

   / PT-425 PTO Not Starting #1  

Husker34

New member
Joined
Oct 17, 2021
Messages
6
Tractor
Power Trac PT-425
Hi everyone, first time posting and did a thread search, but couldn't find a good answer. I've got an older 425 with the Kohler that has 1260 hrs on it (I didn't get a service manual with it either so but blind in that respect). I picked it up last fall and have not had any problems up until today. Tried running my brush cutter and I've got no PTO engagement. I used it a few weeks ago didn't notice any problems and working fine, then today it's dead. Also have no lights at all (haven't for months actually just no time to look into it.... maybe a fuse I don't know where to locate?).

PTO switch still stops the engine from starting if engaged, not sure if that tells me the switch itself is ok. Couplings also seemed to be connected and locked in tight. Hopefully it's a simple fix, something I'm simply overlooking and not a pump failure.

Any insight from the collective experience here would be greatly appreciated!
 
   / PT-425 PTO Not Starting #2  

MossRoad

Old Timer
Joined
Aug 31, 2001
Messages
51,995
Location
South Bend, Indiana (near)
Tractor
Power Trac PT425 2001 Model Year
Welcome to TBN! (y)

So if you turn on the PTO switch, the engine won't start.
If you turn off the PTO switch, the engine will start.

That tells you the switch is working.

With the engine running, you turn on the PTO switch, and nothing happens.

That tells you a couple things:
- electrical power might not be getting to the PTO solenoid.
- electrical power is getting to the PTO solenoid, but it's not pulling in.
- the PTO solenoid is pulling in, but the solenoid valve is bad/malfunctioning/blocked with debris.
- the PTO pump isn't pumping (highly unlikely).

If it was me, I'd check the following:
- Check for 12V at the solenoid with the key in the run position and the PTO switch in the ON position. If yes/then
- See if you can hear/feel the solenoid pulling in when you ON/OFF the PTO switch with the key in the run position. If yes/then
- I'd clean everything around the solenoid valve really well and pull the solenoid from the valve and see if there's any visible debris in the valve body.

If either of those don't pan out, I'd call Terry at PT on Monday for suggestions.
 
   / PT-425 PTO Not Starting #3  

woodlandfarms

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Jul 31, 2006
Messages
6,039
Location
Los Angeles / SW Washington
Tractor
PowerTrac 1850, Kubota RTV x900
My initial thought is you did not have the connectors for the mower in tight. If you flip the switch and the engine dies your valve is working correctly.
 
   / PT-425 PTO Not Starting #4  

m5040

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Nov 23, 2008
Messages
678
Location
CT
Tractor
Kubota M6040 L2250, JohnDeere 310D, Ford 841 Elenco, Ford 961, Trapmaster, PT180 w/LM bucket and 45" brush cutter, PT1430 Deutz w/grapple bucket, Antonio Carraro Tigrecar 6500. John Deere 5300. Former owned Steiner 430 max, Goldoni REV Maxter 7
I would hate to do it, but when it is running with NO hoses attached to the connectors, flip the PTO switch for a fraction of a second and see if the engine lugs down. If it does your problem might be in the mower deck (hyd motor, shaft, etc).
 
   / PT-425 PTO Not Starting
  • Thread Starter
#5  
OP
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Husker34

New member
Joined
Oct 17, 2021
Messages
6
Tractor
Power Trac PT-425
Thanks everyone. I'll try those recommendations and see what might be the issue. I also searched a bit more and saw a post from last year someone had similar issue and it ended up being the battery. The one I have hasn't given me problems so far but it is old and may not be holding enough charge for running PTO.
 
   / PT-425 PTO Not Starting
  • Thread Starter
#8  
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Husker34

New member
Joined
Oct 17, 2021
Messages
6
Tractor
Power Trac PT-425
Well my battery has 11-12v and when I have key on and flip the PTO switch I don't hear anything on the solenoid. Cleaned it up a bit as it was covered in a little grease/dirt. I tested resistance on the solenoid and Im getting about 5 Ohms (although it starts out really high then settles at 5 fairly quickly). Not sure if that's the range it's supposed to be in (anyone know what that should be?). Left key on with the PTO switch on and felt to see if solenoid got hot and it wasn't. I am having a hard time seeing if power is getting to it as not sure where to test that at exactly. Was thinking maybe a ground and the connector to the solenoid. Also had it running (no hoses hooked up) and flipped pto on/off quick to see if engine bogged down and nothing changed.

Didn't have a chance to call Terry today before they closed but hopefully tomorrow I'll get a hold of him. Figured out I have a Sterling Hydraulics solenoid cartridge that was used in an earlier version of the 425.
 

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   / PT-425 PTO Not Starting #10  

ponytug

Elite Member
Joined
Mar 27, 2007
Messages
3,698
Location
Bay Area, CA
Tractor
Power Trac PT1445
Sorry to hear that you are having troubles. FWIW, 11-12V is a functionally dead battery, having 10-20% of its capacity left. It should be 12.6V (Measured between the two battery terminals with the PT off, right?) Nice plots here, the first chart is the most relevant.

So, can you charge your battery for a day or so? If not, can you jump it? If the answer to both is no, buy a new battery, or get a battery charger, preferably one that can do a desulfator process.

I would worry about trying to do more troubleshooting without having enough voltage to ake things work.

Once your battery is charged, you can troubleshoot the rest about whether the battery is old and dead, your alternator is having trouble, your solenoid is in trouble, or you have some bad cables, or grounds. Personally, I am a big fan of cleaning all grounds and battery connections, spraying the terminals/cable ends with battery protection film, putting on copper dielectric grease on the other ends. Having reliable grounds helps electrical items run better, and makes trouble shooting easier. I ran an extra ground from the dash to the engine block, where the negative battery cable ends, and one from that same point to the tub. (Did I mention I hate running down intermittent electrical gremlins?)

All the best,

Peter
 
 
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