I took off + and - wires from the battery post, and follow + and - wires to solenoid terminals. +wires on the left side, -wires on the right side of terminals of starter solenoid. I wasn't paying attention to the wiring on the left side, I had to drop everything I was doing, because I'm allergic to bees and wasp. I went back and connected the starter cable and the + battery cable to the left side of the starter solenoid, and connected the - battery to the right side of the starter solenoid and clip on the coil wire to the clamp, and connected the + wire and - wire on the battery. Before I could even place the bolt on the screw on the - post. A arch flash across the post. I stopped because I think I might have done something wrong. This machine is over ten years old, the model # is where the serial number is suppose to be. Thank you for any information you can give me, in order to get my lawn mower rolling again.

Kathryn Williams, April 2015

I suspect that you have done something wrong.

The starter solenoid is just an electrically operated switch.

A big fat battery positive cable will attach to one big terminal on the solenoid and when the relay (solenoid switch) is operated current is allowed to flow to the starter to turn the engine.

A much smaller wire will carry the control signal to operate the starter solenoid (relay switch) - it will connect to either a separate start button or the start terminal on the ignition switch.

The negative return path back to the battery will very probably be through the chassis of the machine - like it is on most motor vehicles to save the cost of copper wire.

If I read your description of what happened correctly it seems as if you used the starter solenoid as a switch to make a direct connection (a short circuit) between the + and - terminals of the battery - excessive current will have flown for a very brief period.

There will have been high current and heat generated that might - for instance - blow fuses - weld contacts together - melt wires.

It might be wise to have a specialist look at the machine - but you may well have got away with it.

If you carry on yourself - sketch out on the back of an envelope how the wires should go - small control wire to starter solenoid - big power wire from + battery to the solenoid and from there to the starter itself.

The battery -ve terminal usually connects to the frame of the machine.

I know nothing about mowers or engines - no expertise.

Take a second opinion..., April 2015