I have an MTD model 13A4662F129 that won't start. I can jump start it from the battery to the starter, but can't using the ignition key. The key will turn the unit off.

I installed a new selenoid and have attempted to trace the power, but can't find power pass the positive cable entering the selenoid. There appears to be a connection issue, but I am having trouble locating it.

Have you checked the fuse?

I should have mentioned that I have checked the fuse. It appears to be fine.

If you have have a mulimeter, check to see if your getting power to the key switch, then to the solenoid small contact with the key switch in the statr position, it sounds like the key switch is bad.

Or it could be the solenoid itself.