Riding Mower Mystery

[dennis]

I am working on a Poulan Pro Mod. PD22H42ST, Ser. 020704C 002516, MFG ID PD22H42STA riding mower with a Briggs and Stratton Twin V 22HP engine..mod 407577, Type 0283-E1, Code 030821YG. One of those deals where sometimes it runs fine, sometimes not. When sitting in the seat, depressing the Clutch/Brake pedal, it starts and continues to run when pedal is out. It will also continue to run if I engage attachment clutch on dashboard. If I disconnect the seat safety switch and try to start it, it will start, but as soon as I let up on the brake/clutch, it kills. It will also kill if I engage attachment clutch on dashboard. Shouldn't it keep running if clutch pedal is out when the seat safety switch is disconnected?

Also, I am confused by the wiring diagram. The diagram shows two ground wires going to the seat safety switch plug, but there are three. Likewise, the diagram shows to white wires going to Attachment Clutch and four black ground wires. There are only 3 black wires that go to it, and the two whites????

I will be working on it for awhile, checking hoses, filters, carb, etc, so may have more questions on this mower in future. Right now, any help with my questioons would be appreciated.

[KE4AVB]

Yes of course simply disconnecting the seat connector from is going to kill it when you let up on the clutch/brake pedal. It is because there is automatic shorting strip built in the connector. This is to prevent operators from simply bypassing the seat switch by unplugging. The OEMs and OSHA got smart to the operators doing this.

This is an important safety feature as one my customers recently found out the hard way. A previous tech had installed the wrong PTO switch. The customer was mowing his lawn when he got knock off by a tree limb. His mower continue across the lawn smacking his brand new car in the side and it was still running with the deck engaged until turn it off. Could just easily been a kid that it ran over with the deck engaged.

As for the wire count extra wires may just spliced far down in the wiring harness.

[dennis]

Thanks, KE4AVB......I didn't know that. It was a real head-scratcher.

[dennis]

KE4AVB...do you have any idea when they started putting shorting strips in the safety switch connectors?

[KE4AVB]

Those that have been in this business longer than me might know. I started in 2009 and they were there then and the mowers are all older models since I am an independent shop.

[dennis]

KE$AVB....do you know if the seat safety switch connectors are available individually, or do you have to buy an entire wiring harness. I only see them as part of the harness in the Poulan Pro wiring diagrams. Reason I ask is that when I first tried to start riding mower, it started but when I let clutch/brake out it would kill. I disconnected it, and it would still kill (did not know it had shorting strip then). But then when I plugged it back in, I could start it and let clutch out and it would run like it should. I am wondering if the connecter with shorting clip could be going bad. The first time I tried it, when it would not run when I let the clutch out, the connector was plugged into safety switch, and the locking tab was locked (it was plugged all the way in).

[KE4AVB]

The PN for the connector with shorting strip is Delta 96525A-BK. Now with that said you will be hard pressed to find someone that is willing to sell just one.

You are better off just removing the shorting strip and yes they do go bad.

[dennis]

Thank you, KE4AVB. I really appreciate the information and advice.