You can do most of your testing without removing and wires.
At the starter relay/ solenoid use a pair of pliers or two screwdrivers to bypass the relay/solenoid. If pliers just open the jaws and press them against the two big cable studs. This sends full battery power to the starter. Don't even need the key on.
If this spins the starter it lets you know your battery and starter are good.
Now on the relay/solenoid there are two small wires. One is red/white, the other blue/white. When you turn the key on power is sent to the relay on the red/white wire. The blue/white runs to the start button. The start button grounds the wire to spin the starter.
With the key on check voltage at the r/w wire, it should be battery voltage. If so you know the relay is getting power.
Check voltage on the b/w wire. It may be a bit lower, loss through the relay. If good your relay is probably ok.
At this point with the key on, use a jumper wire hook one end to a good ground, touch the other end to the b/w wire. If this makes spins your starter then you wiring on the b/w side is faulty.
The ground path for the relay is on the b/w wire to button, switch housing, to bars, across bars to left side switch housing to a black wire to a harness ground. The usual culprit is dirty contacts between the wire, button and housing.
If so then the pushbutton needs cleaning. Not hard to do. remove the right side control housing. Open it up and see how the push button is mounted. Remove the button. Clean the contacts. Put it back together. There is a metal piece that holds the wire bundle in place. This has a tab that touches the handle bars. This needs to be clean, Where it touches the bars needs to be clean. On the left side you need to clean the tab and bars too.
If you swapped from the stock chrome bars to black bars over the winter, that's the problem. Paint or powder coat is a good insulator of electricity. Open the controls on both sides and remove enough color on the bars so the housing contacts touch clean bare metal.
Leo
