425 mower not engaging

[JurassicJet]

Hello All:

I have a JD425 AWS with about 450 hours on it. Last year it worked well for the most part but occasionally I would have to give the PTO engage knob a good pull to get the mower to work.

This spring, I discovered that the mower will not operate at all. If you pull the PTO knob up the yellow light on the dash illuminates but the deck will not start. There are no sounds that I can hear coming from the electric clutch or anything like that.

Any ideas? I did take the switch out and clean the contacts but I am getting the light on the dash so it appears the switch is making contact.

 

[beenthere]

Will be interested in what you learn. I've a 424 AWS but no problem yet with the electric clutch.
Later today I may be able to browse the tech manual CD and try to find a clue for you to work on. What is the S/N of this 425 (leave off the last three digits for security) ?

 

[JurassicJet]

Well... I just went through the wiring and do not see any anomolies near the front of the tractor. Took the connectors off and cleaned them where I could. It appears that the wires from the PTO switch go into the circuit board on the right side of the tractor.
There is a green light and a red light on the panel. Any ideas what they mean?

I am going to have to remove the seat pan and gas tank to get to the wires that go into the tranny, and I don't feel like ripping that all apart today. I have a feeling that I would not find any issues under there anyhow.....

the serial # is M00425B071. It is a 1999 I believe. Thanks!

 

[Kyle_in_Tex]

Check the seat switch really good, it it one of the safety lockouts. If it isn't depressed, it won't engage I believe.

 

[MarkV]

If the battery is the least bit weak it can cause the electric clutch to not work. On my Cub I can have enough battery to start the mower but not enough to handle the draw of the electric clutch.

MarkV

 

[JurassicJet]

Kyle_in_Tex

Check the seat switch really good, it it one of the safety lockouts. If it isn't depressed, it won't engage I believe.

I have that switch bypassed (am i supposed to say that on here?)

I will have to check my battery Mark. I know that the terminals are real corroded and that was on my spring to-do list. I will give you a report in about an hour or so...

 

[zzvyb6]

I have the same guts in a JD front mower (Its a 425 running backwards).

Check to see if the parking brake is set or the brake lever is out of position. The machine may think the brake is on. Mine has a microswitch sensor. Once the band slipped off the rotor and the switch did not close.

 

[JurassicJet]

As far as the brake is concerned... When I apply the brake when traveling forward (and the PTO is illuminated on the instrument panel) the light extinguishes, which would cause me to believe that the brake switch is making the correct connection.

 

[JurassicJet]

I completely cleaned the battery terminals and re-installed the cables. Unfortunately no change. Mower still does not work so now I am running out of ideas.

 

[Dutch445]

One difference with these units is they don't have
an electric clutch. there is a hydraulic clutch in the
transmission.
there is also an electronic control panel on the right
side of the steering column with some lights, red/green.
there are relays on the board, and i was experiencing
intermittent problems with pto engagement until i replaced
the circuit board. at the beginning, i think i remember that
i was able to tap the relays and the deck would come on.
look into that area and see if you come up with any more
info. double check the lights that come on and when.
(the red/green ones)

 

[beenthere]

Dutch
Interesting you say hydraulic clutch. However there is an electric switch to engage the clutch, so that may be where the thinking is that it is electric.

I thought it was electric, that the switch would activate a magnet that would either release or engage the clutch plates in the transmission.

Can you fill us in with more detail how that PTO clutch works?

 

[beenthere]

Well... I just went through the wiring and do not see any anomolies near the front of the tractor. Took the connectors off and cleaned them where I could. It appears that the wires from the PTO switch go into the circuit board on the right side of the tractor.
There is a green light and a red light on the panel. Any ideas what they mean?

I am going to have to remove the seat pan and gas tank to get to the wires that go into the tranny, and I don't feel like ripping that all apart today. I have a feeling that I would not find any issues under there anyhow.....

the serial # is M00425B071. It is a 1999 I believe. Thanks!

Appears this tractor has the reverse shutdown switch. Has it been disabled, and is somehow acting up now?
Attached the PTO schematic if that might help. If more on the trouble-shooting section of the PTO is of interest, I can post that as well.

 

[beenthere]

Here are some additional pages from the tech CD that might help. Wondering if it could be the solenoid valve too, or a wire going to it?

 

[Scotty370]

Have you checked the air gap adjustment in the Electro clutch? Check my prior thread on simular problem on 318. http://www.tractorbynet.com/forums/...44369-jd-318-intermittent-electro-clutch.html

 

[zzvyb6]

Book says to put 12v on the pto clutch solenoid after disconnecting from main circuit and listen for a click. Check clutch ground, too.

 

[JurassicJet]

Beenthere - Thanks for those troubleshooting pages. I think I am going to print those little puppies out!

The problem now guys is that I am at work for the week so I will not have a chance to troubleshoot until next week. Grrrrr....:mur:

 

[Dutch445]

Scotty,
that's the difference from the electric clutch to the hydraulic,
there is no air gap adjustment. the clutch is enclosed in the
transmission and quite durable.

but, there may still be an electrical problem getting there,
there is the solenoid that activates that clutch

Have you checked the air gap adjustment in the Electro clutch? Check my prior thread on simular problem on 318. http://www.tractorbynet.com/forums/...44369-jd-318-intermittent-electro-clutch.html

 

[a.palmer jr.]

One difference with these units is they don't have
an electric clutch. there is a hydraulic clutch in the
transmission.
there is also an electronic control panel on the right
side of the steering column with some lights, red/green.
there are relays on the board, and i was experiencing
intermittent problems with pto engagement until i replaced
the circuit board. at the beginning, i think i remember that
i was able to tap the relays and the deck would come on.
look into that area and see if you come up with any more
info. double check the lights that come on and when.
(the red/green ones)

I was wondering what all that stuff on that circuit board was for.

 

[Scotty370]

Dutch - That's what I was afraid of. Just tryin' ta help if they were simular designs! ~S

 

[JurassicJet]

Ok. Got it figured out. It was the solenoid in the rear of the transmission that engages the PTO. It was bad and replaced. Works great now :thumbsup:

Only problem is the dang thing was $100 from the JD dealer :shocked: