ok, This is for a 1992 sportster. The back turn signal constantly flashes when the bike runs, if I hold the switch in it will shut off. if it's on but not running the turn signal works normally. It's only when it is started

Ive rewired the ground, re wired the positive and still the same, I also unplugged the sides and switched them and it flashes, so it's not the ground wire, positive wire (from the wiring harness back) or the turn signal it's self

 

Could you please explain that in a less confusing manner?

 

One Back turn signal is constantly flashing
I've re wired the positive and negative but it still flashes constantly when the bike is running.

 

I suggest you solve the simple, cheap problem first...The front signal should also be flashing, because both signal lights are on the same circuit.

The reason the front is not flashing is because there is a problem somewhere in the circuit.

Although the signals are on the same circuit, the front signal is a long distance from the turn signal module, the voltage must pass through two connectors.

Check these two connectors, make sure the wire terminal has not backed out of the connector.

 

The front stays on not flashing if the bike in on but not running. When running it flashes.
I'll trace down the connectors today

 

Remove the battery, clean all cable connections, make sure the battery is fully charged and have it load tested.

Once the battery is back in, perform a charging system test.

 

Just tried the battery bit you mentioned. It was good cleaned it and put it back on. Still flashing.
Also no loose connection I could find.

 

Which side is flashing constantly.
Is the turn signal indicator in the dash flashing?

 

Right side front and back and yes the dash is also flashing

 

Unplug the electrical connector from the turn signal module, turn ignition switch on.

With your voltmeter, read the voltage at the terminal for the brown wire, you should read:

Zero volts when the turn signal button is not pressed.
12v when the button is pressed.