Electrical Ghost in cub zero turn

[Benhoff27]

I have an older cub zforce 44 zero turn. It's been a great mower up till now. Have an issue that appears to be a safety circuit issue, but after checking or replacing (or temporarily jumpering) the switches the issue is still there.

Mower will start fine. When brake is removed the engine cuts out. I had this issue at first mow this year, replaced one bad reverse cut out switch and the mower worked great. Next mowing it stalled mid mow and couldn't pull brake off at restart. Sounds like a seat switch but I've replaced it, bypassed it temporarily, and used multiple switches (which I know work) so I'm at a loss. The only thing that doesnt work well is if brake is on and I try to engage PTO, PTO turns on then engine dies. Could it be some electrical fault in the clutch causing the safety circuit to trip? Ran through all the safety circuit tests and everything else works as it should. Help!!

 

[ILENGINE]

Everything leads back to a seat switch issue. May need to go through the wiring looking for a rubbed wire. A wire making intermittent contact can drive you nuts.

 

[bertsmobile1]

Have you downloaded the the wiring diagram that you will find at Cub Cadets & More web page so we can be singing from the same song sheet ?
When you have then get back & we can go through the electrical troubleshooting .

 

[Benhoff27]

Here u go. I have the manual but pic was too big. I may take ILEngines suggestion. At this point I might just replace harness. Thanks for the help.

 

[Benhoff27]

I also replaced PTO switch and brake switch to eliminate the issue. Still same problem.

 

[bertsmobile1]

The ghost in your case resides in the yellow / yellow-black wires
From the circuit diagram you see the magneto gets killed via the seat switch & the parking brake switch
The path is ground > green wire >brake switch >yellow / black wire> Seat switch> yellow wire > magneto
When the brake is off the green & yellow / black wires are connected together so the seat switch should show ground on the yellow / black wire side
If the seat witch is working and you are in the seat there should be no connection between the yellow & the yellow / black wires
If you are not in the seat then the yellow & yellow / black wires get connected & the magneto is grounded .
Take the seat switch out and check that is is open circuit plunger down & closed plunger up
Start the engine and release the brake or jump the green to the yellow black at the plug ( it will not crank if the plug is removed first ) then manually hold the seat switch plunger down , then let it off every time you let it off the engine should shut down
If the switch checks out OK then it will be the wiring ( yellow wires ) from the seat switch to the magneto
On your machine you check this by unplugging the seat switch & starting the engine then jump the plug
Every time you jump the plug the engine should stop if it stops with the plug open then there is a short to ground between the seat switch & the magneto.

Seat switches on ZTR's take a pounding and do give more troubles than on tractors
There are two cut out circuits that run in parallel with each other
PTO + SEAT + MAGNETO
BRAKE + SEAT + MAGNETO

PTO & Brake are not in a circuit themselves but both provide a ground to the seat switch

 

[Benhoff27]

The ghost in your case resides in the yellow / yellow-black wires
From the circuit diagram you see the magneto gets killed via the seat switch & the parking brake switch
The path is ground > green wire >brake switch >yellow / black wire> Seat switch> yellow wire > magneto
When the brake is off the green & yellow / black wires are connected together so the seat switch should show ground on the yellow / black wire side
If the seat witch is working and you are in the seat there should be no connection between the yellow & the yellow / black wires
If you are not in the seat then the yellow & yellow / black wires get connected & the magneto is grounded .
Take the seat switch out and check that is is open circuit plunger down & closed plunger up
Start the engine and release the brake or jump the green to the yellow black at the plug ( it will not crank if the plug is removed first ) then manually hold the seat switch plunger down , then let it off every time you let it off the engine should shut down
If the switch checks out OK then it will be the wiring ( yellow wires ) from the seat switch to the magneto
On your machine you check this by unplugging the seat switch & starting the engine then jump the plug
Every time you jump the plug the engine should stop if it stops with the plug open then there is a short to ground between the seat switch & the magneto.

Seat switches on ZTR's take a pounding and do give more troubles than on tractors
There are two cut out circuits that run in parallel with each other
PTO + SEAT + MAGNETO
BRAKE + SEAT + MAGNETO

PTO & Brake are not in a circuit themselves but both provide a ground to the seat switch

Thanks Bertsmobile! That helped me narrow the issue down. Pulled the covers off the harness and traced wires. Checked continuity from engine plug to seat switch and had continuity. Checked the opposite side of the plug and still had continuity. Turns out there was a tiny metal spring in the plug that had worked it's way across both leads. Pulled that out and is working fine now. Thanks for the motivation and helping narrow down the issue! Now I can bypass it until i get a new plug end.

 

[bertsmobile1]

Glad we could be of service
Switch comes as a unit but be careful that you get the correct one as the open > closed ones are identical to the Closed > open ones
Be very careful using the mower without a functioning switch as it is the only thing that protects both you and others around you should you fall off .
I have seen mowers running down the road being chased by the owners and had one owner who tried to mount from the discharge side with the expected results
IT took him several years to learn to walk again

 

[Benhoff27]

Glad we could be of service
Switch comes as a unit but be careful that you get the correct one as the open > closed ones are identical to the Closed > open ones
Be very careful using the mower without a functioning switch as it is the only thing that protects both you and others around you should you fall off .
I have seen mowers running down the road being chased by the owners and had one owner who tried to mount from the discharge side with the expected results
IT took him several years to learn to walk again

With that mini spring pulled out the plug still fits on snug and the switch functions as it is supposed to so I didnt have to bypass anything. My guess is that spring was to hold some plug tension on the switch prongs but a screwdriver and a little bending of the leads did the trick. I'll check it here and there and might throw some tape on it just in case. Thanks again!