See if your machine has an electrical switch or button to push to make the mower deck come to life! Does it have an electric mower on/off switch? Check all wiring, look for a worn wire, making unwanted contact with the metal frame or body. Follow the mechanical linkage, to find that switch.

get the full model number of yer tractor from off under the seat. go to sears parts, get a .pdf on the owners manual - may be an electrical diagram in it to help.
But, yer prob description could mean a faulty seat switch... or transmission neutral switch prob. There may not be such a thing as a dedicated clutch switch on your unit... ?

rcbe's suggestion on the seat switch is the most logical and easiest to find! A basic ohmmeter will tell you if the switch is working. Just check it in both positions. And unplugging it won't help. Most times if it cranks- the clutch switch is working The clutch switch will be activated by a piece on the clutch shaft- so it is in that easy to find area just under the pan....

If it's a manual engage type (lift the lever over the hump), you can usually tell by slowly lifting the lever the blades will start to turn slowly and speed up the higher you life the blade engagement lever putting more pressure on the deck belt, if the blades come in all at once you got an elect clutch (some model craftsmans has level/elect clutch system and just not the buttom to pull or push in), plus you will see elect. clutch on the end of the engine crankshaft and two elect wires will be going to it. If manual type usually the PTO clutch switch is behind the dash, you will probably have to remove the battery or gas tank depending on your model to see it. Just watch the lever as you lift it, somewhere along it it will hit a red bottom which is a very simple switch, either it's on or off. so tom's suggestion of checking these with a muli-meter is easy to do providing you understand the muli-meter and switch operation? Beings the switches are usually wired in series isolation of and individual switch is more difficult due to the wiring somewhere maybe chafed and touching a metal part giving a grounding condition.

There maybe another switch down on the frame when you push the clutch/brake in you can usually see the little red buttom, again using a flash light and following the clutch lever linkage along it path to the idle pulley assy, that disengages the engine from the transmission. IMO the wiring diaphram will only show the electrical conponents and will not tell you where they are located on the tractor, you have to have general knowledge of system to figure out where they might be located based on you mechanical knowledge.

Thanks for the input everybody. The wiring diagram does not show the location of any of the switches on the frame nor does it specify what any switches are for, though I think I've found the suspect switch on the diagram. It's not the seat switch--I've bypassed it (I'm not using the tractor to mow, just to pull a trailer).

It's not the attachment lever switch either. I left that one alone, but it works fine and is out of the loop anyhow.

I've also looked at the entire clutch linkage front to back and I can't see any switches, not even any wiring, anywhere near any rod or lever that the clutch pedal moves.

I've also asked at three different mower repair centers and nobody knows where it is.

I must have the only one of these ever made! I was hoping somebody here had specific knowledge but thanks for the suggestions! I'll find that bugger sooner or later.

Why the mystery? Give us the model numbers and you will probably get an answer.

So, how did you bypass the seat switch? There are special terminals that require the switch to be plugged in. Is yours meant to be normally open or normally closed? The clutch switch is located in the area of the the clutch pedal assy- though maybe the far side of the pedal, not in the back. Many have 4 terminals 2 open and 2 closed. Does yours have an operator presence relay?

mine is an older unit, it is attached to the top of the frame pointing down, can only see the moving end from the bottom. you may have to whip all the crud off to see it. I agree at least give something to go on. like model number (under the seat) series numbers (Like LT1000, 2000, ect. or DLT2000 ect...Some of sears LT's only have model number under the seat (lift it up and wipe the crud off) so people couldn't compare prices to other brands, these were usually lower end models Like LT or DLT 1000's or 2000s?

Switches are easily bypassed by jumper wires, drilling a hole inserting a small screw locking the buttom closed, or just cutting wires and wiring them togather as I've seen, this is what makes old LT a pain to work on cause you never know what your getting? LOL!

the switches are there for a purpose and are still available and relative cheap 4 or 5 bucks in most causes, I don't understand why so many people bypass them there are there for our safety? like replacing a light switch in our home! either it's on or off, we don't bypass light switches???????? OK maybe some even do that! That would be the extreme fire hazzard!!! wouldn't it! I never had alot of money, but I never skimp on things I that needed fixen!

The switch is mounted to the tractor body under the hood with the button facing down. The easiest way to access the switch is to remove the 1/8" roll pin on the right side, slide the clutch assembly to the left in order to push the switch down. The roll pin is a pain, I took an 1/8" roll pin punch and welded it to an 18" piece of re-rod in order to have some swing on the punch.

can't find it

Can you find the model number of the machine?
It should be on a data decal under the seat or under the hood.

If your tractor is a 19.5HP rider, then you will find the brake/clutch sw under the solenoid witch is under the battery on the right side

If the engine dies when you move the clutch pedal, then it would mean that the clutch switch is working.

My older LT1000 starts without a problem. If I start to engage the blade or release the clutch, the engine stops. This is an intermittent problem.