Ignition Switch

[bradandrose]

I just bought a used Husqvarna 2100.  The saw runs great but the ignition on/off toggle switch doesn't seem to work.  The saw starts and runs regardless of what position the switch is in.  Even if I disconnect the single wire from the back of the switch, the saw still runs.  The only way to turn the saw off is to choke the motor and let it die.  Anyone have any idea what the problem is?

[Kevin]

If you had an ohm meter you could test the switch and the wiring.

[HARD_WATER]

how old is the saw?? or you can just replace the switch i think thats the problem

[Minnesota_boy]

The switches on the saws work by shorting the wire to ground.  Try making contact with the saw frame (bare metal) with the wire when the saw is running.  If it don't stop, you have a broken wire.  If it stops, put in a new switch.

[bradandrose]

I do have an ohmmeter, but the strange thing about this switch is that it only has one wire going into it.  There should be two, unless maybe it switches the wire to ground.  What exactly does the ignition switch do?  Does it short the power meant for the spark plug to the case to prevent the plug from sparking?  If I knew exactly how the ignition circuit works I'd be able to troubleshoot it better.

[bradandrose]

Thanks Minnesota_Boy.  I was writing my respone to the first two posts when your reply came in.  You confirm my theory.  I'll check that tonight.

[Kevin]

The switch is just one wire in and the other side of the switch is chasis ground.
When you close the switch it puts a ground from the chasis on the wire which kills the engine.
It may have been modified somewhere along the circuit by the previous owner or it is a simple malfunction.
With your meter leads on each side of the switch you should be able to see it open and close.

[Stephen_Wiley]

Hey Hard Water & Brad and Rose,

Welcome to the forum,  don't know if anyone else has noticed your new presence, yet.

Hard Water - See your from  Staples..........My Grandfather lived their till his teenage years than moved out here to Oregon.  Never heard him talk to much about the area, other than the farming he did.

[Viking]

bradandrose, take of the side and follow the wiring from the switch, and see if it has come unplugged some place along the way, ive seen that a few times.