Re: How\'s An Ignition Switch Work?
Check the blue wire for continuity from the flywheel (magneto located under the flywheel) to the ignition switch. The switch itself could be lacking a proper ground and/or the terminal on the rear of the switch could have corrosion on it and not be making proper contact. Since you have the problem with the new switch as with the old switch, I would reinstall the old switch so you know that it is correct for your application. You could also verify the new with the old by comparing the markings on the fiber board backing where the terminals come out of the switch. I would hate to think that you have compounded the problem with a wrong switch. If the old switch were defective and the new switch doesn't have the identical contact connections, this alone could be the problem. Never assume that a electrical product is the same because the external view is identical. The internals could be entirely different. If you have the wrong switch and have disposed of the old switch, then take the wiring schematic to a lawn mower shop. They can look up the proper part number and get it for you. Don't expect that they will have it in stock, because there are many different switch's and it isn't practical to stock them all. Depending on the popularity of the switch, it can cost between $6.00 and $26.00!!!!!!!! /forums/images/graemlins/frown.gif
I would simplify the entire testing procedure by removing the blue wire from the wire terminal end and grounding it directly. This can be done by using a very small flat bladed screwdriver to release the tang on the terminal in the plastic connector, or you could just use a piece of wire and "shove" it into the back of the terminal connector and touching the other end to the ground. Bare about 1" of wire at each end of the test wire for this beforehand for this operation. If the engine shuts down when you touch this wire to ground, it indicates a defective switch. If it doesn't, then it is a defective wire from the switch to the magneto. If it is the wire from the switch to the magneto, it will be quicker to just install a new wire bypassing the defective wire since this defective wire is bundled into the wire harness. If you find a break near the magneto, then splice, solder the connection and tape or shrink wrap the repair.
