Repairs LT2045 Brake Pedal Interlock Problem - stalls when releasing brake pedal.

[CT-Ken]

Hello - newbie here, but not to auto and other mechanical/DIY forums. I recently picked up a lightly used, well kept, Snapper LT2048 Hydro. The numbers are - Mod: LT200H48IBV2, B&S model: 84897, s/n 50199623. It's got a 48 deck, B&S 20HP ELS Twin OHV. From the codes I see, my guess is that it is a 2004 vintage tractor. Everything worked fine during testing before purchase, and again when I got it home. I did some pm and made some simple repairs in the last few days, and now I have a brake pedal interlock problem, and a reverse lockout override problem.

I made some seat mounting/base repairs, replaced the air filters, sharpened the blades, lubed it up per the owner's manual, and did some basic cleanup. When I fired it up to test everything out, I ran into my first problem. The tractor fires right up normally, when the brake pedal is pushed down, or locked down. But as soon as the pedal is released, some interlock is shutting the engine down. If I push the brake pedal back down, it will not stall. I checked all the wiring, including anything I touched, and all is intact and unmolested. Not finding anything on my first pass, I removed the deck, and dug deeper. The pedal is depressing the brake pedal switch correctly, and allowing the tractor to start. As soon as the brake pedal switch is released, it stalls. I don't see any other interlock switches in there related to the brake pedal. Is there some kind of sensor somewhere that is causing the engine kill when the brake pedal is released? Is there a way to test the components that may be causing the problem? Is there a quick way to temporarily circumvent the kill, such that I can move it around and/or use it? Any help on this problem will be appreciated.

Also, this tractor has a reverse lockout & override. When moving forward, with the blades turning, the reverse lockout is supposed to prevent shifting to reverse. The override is supposed to allow temporary forward and reverse operation, while the blades are turning. It looks like there is a spring loaded solenoid, near the shift lever, that prevents reverse operation. The solenoid does not appear to be working, as the engaging lockout lever does nothing. Can someone advise on how this reverse lockout & override is supposed to work, and is there a way to test it? The tractor had this problem when I tested it before purchase, so I don't believe it is related to any of the maint that I performed.

Thanks in advance for any and all help!

Ken

Edit - title incorrectly says LT2045. It's a LT2048.

 

[CT-Ken]

FIXED - LT2048 Brake Pedal Interlock Problem - stalls when releasing brake pedal.

Determined to fix this problem, today I gathered up my operator's manual, parts list, wiring diagram/schematic, multi-meter, etc, and set out to find a solution to my problems.
I was able to solve the problems, such that all interlocks now work, the reverse lockout works, and the reverse lockout override works.

When I replaced some broken seat base parts (the rubber spring cover - 7019109YP, and the seat cushion holder - 7028580YP) I had to disconnect the harness from the 2 interlock switches that are under the seat. One switch is BLACK, the other is GREY. The harness connectors are black and gray. The black connector has red-red wires. The gray connector has yellow-blue/blue wires. The schematic advises to connect the red-red wires to the GREY seat switch. The schematic advises to connect the yellow-blue/blue wires to the BLACK seat switch. This means you should connect the GREY connector to the BLACK switch; and connect the BLACK connector to the GREY switch. I could have sworn that the connectors matched the color of the switches when I took it apart. But, that's not possible since the problem only started after I put everything back together.

I then tested the reverse lockout mechanism, and it is working properly. Additionally, the reverse lockout override also works correctly. However, the manual says that the override will remain in effect until the blades are stopped. That's not how mine is working - the override releases after some random amount of time, even though the blades have not stopped.

If you experience an engine kill upon releasing the brake pedal, the connectors under the seat to the two switches probably have been inadvertently reversed !

 

[mechanic mark]

Good post & information, thanks.