starter wiring diagram for 1993 honda shadow 1100

So that is what the circuit does - it provides a series of pulses to turn the SCR on, but it also shorts the input and output - but it does this through a capacitor and a resisitor. There is no need to because once the SCR is on, it stays on - unless the voltage falls to zero, which can be achieved as I said - shorting out the input and output. So it keeps turning the SCR on if the engine is running. The Current acting on the trigger is alternating current so it keeps getting a stream of pulses at very frequent intervals. Which in this case turns the fuel pump off. As soon as you connect those two together, the input and the output both fall to zero - which turns the SCR off. (If I knew what I was talking about, I would call them anode and cathode, but if I did, I know that I would get them confused, and not everyone knows what anode and cathode mean. One way of turning it off, is to short out the SCR - ie attach the input leg to the output. Once it has been turned on, it cannot be turned off - unless the voltage passing through the SCR falls to zero. It does not allow current to pass at all in either direction, unless it receives a voltage on the trigger wire. This behaves as a normal rectifier - allowing current to pass in one direction only - except it has a 'switch' - in the form of trigger wire. The fuel pump on the ST1100 is controlled by a circuit which has an a SCR - a silicon controlled rectifier. I had a look at this a while ago - so this is from memory and may be slightly inaccurate.

Starter wiring diagram for 1993 honda shadow 1100