Won't run when brake is released.

[Kevin Toadman]

Ok, I checked the brake switch, blade switch, seat switch and bypassed also and when the brake is released the engine dies. I tried a spare ignition switch just to see and it worked for one start then back to the same thing. This is a 1998 Craftsman 19.5 mower with a two prong seat switch. Any ideas? Thanks.

 

[bertsmobile1]

Not until we know which model
From 1998 it could have been made by Murray, MTD, AYP, or Noma and every one has a slightly different wiring .
Basically if releasing the brake kills the engine then that points to the seat switch ( or the switch wires ) .
A second test can confirm it by sitting on the mower starting the engine then turning the blades on.
If they will not turn on or turning them on kills the engine then that confirms a seat switch problem .
But to be specific we really need the numbers off the ID tag under the seat .

 

[Kevin Toadman]

Thanks for the reply. I'll post the tag info tomorrow when I'm back home. I did jump the seat switch with a jumper wire, it's just two prongs. Thanks again.

 

[bertsmobile1]

Thanks for the reply. I'll post the tag info tomorrow when I'm back home. I did jump the seat switch with a jumper wire, it's just two prongs. Thanks again.

dependig upon the exact wiring the seat switch can be normally open or normally closed
One needs to be jumped to simulate you being in the seat while the latter needs to be disconnected to do the same thing.

 

[StarTech]

Being a Craftsman most likely it got the grey seat switch which is a NC switch and the seat switch connector has a built-in shorting strip. Otherwords jumping the switch just or simply unplugging the connector makes the mower think there is no operator present. The shorting strip was install in the connector to keep someone from simply unplugging the connector. IF the connector locking tab is broken off the shorting can activate on its own. Also these shorting can become damage requiring the connector to be replaced. Replace connector housing is available through Stens under PN 430-057

If you have the black seat switch then it is a NO switch.

Either way both are Delta 6440 style switches.

 

[Kevin Toadman]

Thanks both B and S for the replies and info. I was unaware of the shorting strip, that explains why jumping it didn't work. It does have the grey switch. I attached a couple of pics. Thanks for the part number for the connector also.

 

[Kevin Toadman]

Well, I appreciate all ya'lls help. I popped out the center spring clip thing from the center of the switch connector and bingo, it works. I was totally unaware of the "shorting strip" until I learned on this forum. I thought it was just a regular connector but it's certainly not. I had already ordered a new switch so now I'll have an extra. Thanks again!!