Engine dies when I disengage the brake...

grantiman

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I have an older Cub Cadet Z-Force zero turn mower, model # 17AF3AGV010. I just put in a new starter and it started right up, problem is, every time I disengage the brake the engine shuts downs, put the brake back on and the engine starts back up again. It'll run on idle without a problem, as soon as I release the brake it dies. It ran fine before I put the new starter in, any ideas where to start troubleshooting?
 

Auto Doc's

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Seat switch or one of the handle lever safety switches has the bracket tab bent back out of place. Mine has done that with the right handle control safety switch a couple of times. I need to weld the switch tab to strengthen it back up when I have time.

The park brake switch tab may also be bent back from age and that will do the same thing.
 

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Sorry, that request gets "crickets" from most techs.

It automatically opens us up to liability and possible legal issues.

It is dangerous to bypass any safety switch and too tempting to leave it that way.

Maybe some DIY hack online has the answer.
 

StarTech

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As noted it is a liability issue to tell someone how to permanently disable any safety switch. Beside I done had insurance company try to hang me with the bill about an issue I found after DIYer installed the wrong switch. [the customer after the accident brought the to my shop to find why it didn't stop]. The result was that the customer was mowing, got pulled off the mower by a low tree limb, the mower just kept mowing until it rammed his wife's new car.

From Service Manual that explains the operation of the switch circuit.

1757882501942.png
This is just for the initial release of the parking brake. There is a different circuit that involve the lap bars in neutral position. They only affect starting and kill the ignition if they are move from neutral position while the parking brake is engaged.
 

grantiman

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As noted it is a liability issue to tell someone how to permanently disable any safety switch. Beside I done had insurance company try to hang me with the bill about an issue I found after DIYer installed the wrong switch. [the customer after the accident brought the to my shop to find why it didn't stop]. The result was that the customer was mowing, got pulled off the mower by a low tree limb, the mower just kept mowing until it rammed his wife's new car.

From Service Manual that explains the operation of the switch circuit.

View attachment 71849
This is just for the initial release of the parking brake. There is a different circuit that involve the lap bars in neutral position. They only affect starting and kill the ignition if they are move from neutral position while the parking brake is engaged.
Thank you for all the info. One other quick question if you don't mind. When I have the mower running and the brake is on, would you know if the PTO should engage, if I turn on the PTO the motor also dies, wasn't sure if that had anything to do with my problem.
 

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Read the manual from Cub Cadet. They are free online. Look it up by you label number you provided earlier.
 

StarTech

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Oppps I gave some bad info. The service manual I have does not cover the Z Force 48 so no relays used just switches. But the info is correct on the operation just done a little different. Also seat switch connector will contain a shorting strip and if loose can cause your problem.

So here is the two possible wiring schematics. Same diagrams just laid out differently.

1757896493132.png

1757896575983.png
 
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