PT-425 PTO Not Starting

[Husker34]

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!

 

[MossRoad]

Welcome to TBN!

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.

 

[woodlandfarms]

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.

 

[m5040]

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).

 

[Husker34]

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.

 

[MossRoad]

Good luck. Please let us know what you find out whenever you get a chance. Thanks.

 

[woodlandfarms]

Those valve coils do pull a lot of juice.

 

[Husker34]

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.

 

[MossRoad]

Good troubleshooting so far.

 

[ponytug]

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

 

[MossRoad]

I didn't read the low voltage report until I read your reply. I just had a battery replaced in my Impala. It wouldn't go past about 12V.

 

[ponytug]

@Husker34 In the minor FWIW category, Ohm's law is V=IR, or I=V/R, so 12V/5ohms= 2.4 amps, about what many solenoids draw, so you are in the ballpark on the solenoid resistance.

All the best,

Peter

 

[Husker34]

Well I spoke to Terry today for a few minutes, after I installed a new battery (no change to problem). I tested a connection back towards the switch and was getting about 2v. I had to hang up with him and pulled the panel to look in at the switches. Prior owner had ordered a new ignition switch and had not installed it, so I figured good time to do that. I reached back in (forgot I had key on still) moved the wire to ignition and there was a spark...damn! Then engine wouldn't turn at all (new fuse fixed that).

So killed power from battery and took out the plug and saw the wire running from harness to the PTO switch was hanging by a thread or two.... literally. I got all that pulled out, put new ignition key in and reattached wire to harness how it's supposed to be. Then the wires running to lights were loose and tightened them up with a new connector. Got all back together and..... engine just cranks and won't run.

So do some diagnostics on ignition key, it has same plug configuration, but figured out it's got different diagram than original one but looks practically the same. So I popped in old one after I dug it out of the trash and plugged it in and I have engine power, running lights again and PTO seems like it works again (finally heard the click when I had key on engine off and flipped on PTO switch).

I think I'm back in business but going to have to figure out a new situation for the old ignition key. Thanks for all the help and input everyone!

 

[Husker34]

Also, seems as though the key assemblies may look the same but there are different internal wiring options after doing a quick search. The new one I had has 6 posts and the old one only 5 posts. 6 post would just crank and crank and 5 post let's it fire right off.

Oh and prior owner did a little modification.....chopped a hole in the back lower to be able to pull the battery. Unconventional but it works.

 

[ponytug]

I am glad that you got your tractor running. Congratulations!

if it were me, I would keep an eye on that battery hole, as square holes in corners are notoriously weak, and sources for cracking.

All the best,

Peter

 

[MossRoad]

As I recall, I had to replace the ignition switch on my 2001 425 about 10 years ago, and I had to do a little paper and pencil thinking to get the connections correct.

Glad you got it going.

As for your battery... is your's like mine in that you have to remove the muffler to get it out if you didn't have that custom access port?

 

[Husker34]

I would definitely have to take out the muffler to get the battery out. It definitely is not as good integrity strength wise as he also built a counterweight he attached to the hitch pin. It's bent/bowed because of that. I may employ my brother in law welder to strengthen it back up and create a better way to quickly attach/detach the counterweight (about 70lbs I'd estimate). It definitely helps with moving heavy dirt.

 

[MossRoad]

Mine is similar, in that I have to remove the muffler. 3 batteries in 21 years. Last time, the exhaust stud broke off instead of the nut coming loose. I had to weld a nut to the stub to get it out. Kind of a pain in the rear.

However, with all of the quirks and such, I'd buy it again. Just too handy.

 

[cqaigy2]

I don't recall what model ignition switch i got, but it seemed like a direct replacement. I think i posted in your niffty thread about replacement part Moss

 

[cqaigy2]

oh and replacing the battery for me is pulling the gas tank off, then snake it up and out through there.