Cub Cadet Z Force 44 will not crank/start

A friend I sort of look after has a Cub Cadet Z Force zero turn mower that will not crank/start when you turn the key switch to start. The starter is good as it cranks when it is jumped. I assume the problem is in some safety device like the switches on the steering levers, PTO button, parking brake, or seat. Can someone give me an idea where to start? I don't think they have the money to take it to a shop.

This post was edited by geok on 06/05/2023 at 06:39 am.

Here is the order I usually use:

1. load test the battery. (I know you said it works when jumped, but just to be sure. A weak battery can lay down and play dead if asked to power multiple circuits at once.)

2. find the starter solenoid. Some are on the starter, some are mounted separately. With a test light or a voltage meter connected to ground, see if you have power to the small terminal(s) on it when you turn the key to 'start'. Assuming it has only one small terminal, If you have power there with the key in start, the solenoid itself is bad.
If your solenoid has two small terminals, disconnect them from the solenoid and test both wires. One wire will be a ground. Sometimes the ground wire is part of the safetly switch circuit.

3. If still no start, and the ignition switch is easy to access, check for power on the red wire in the plug. (Red is usually battery positive wire at the ignition switch.) If no power on the red wire, check for a blown fuse.

4. Then re-connect the ignition switch plug and backprobe the plug to see if you have power on the yellow wire when the key is in 'start'. (Yellow is usually the start wire on a Cub Cadet.)

O.K. That is all the 'easy' part:

5. If all this fails, you will have to trace the start circuit through the pto, seat, left and right handle and park brake switches. It is usually the yellow wire that goes through all these, but sometimes they change wire colors between components. (The worst one ever was a husqvarna that alternated orange and yellow wires through all the switches. It took a long time to figure that one out.) Soemtimes they incorporate a relay in the start circuit, just to multiply the confusion. But eventually the power makes it all the way to the starter solenoid through all the switches.

Our Cub Cadet Z Force S had the mower electric clutch develope an internal short and was blowing fuses as fast as you could change them. Had to install a new clutch. It would not crank of course.