Now then, after much banging of head against wall with what seemed like a simple electrical problem, I`m at a loss and I thought I`d ask for your help. It`s a bit of an epic so please stick with me.

I know that there are some oracles of all things electrickery on here, so I humbly ask for your help, here goes.....



If I turn on the ignition and operate the indicators without the engine running, they work perfectly.

If I start the engine, they stop working.

If I turn on the sidelight with the engine running, they will work sometimes, others not.

If I turn on main headlight with the engine running, they will work perfectly.

If I disconnect the headlight with the engine running they stop working but will start working again if I put the plug back on the bulb.



I`ve also tried three different flasher units - exactly the same problem with all of them.
O.k. so I`ve double checked everything. All earths and connector blocks seem good and I went as far as stripping the whole headlight area and took all the insulation off the front of the loom back to the headstock to look for chafed wires. I found one, which was from the engine stop switch on the right hand side so taped that up but everything else looks fine. I also took the ignition switch to pieces and cleaned it out and freshened up the contacts There are a couple of repaired wires in the front part of the loom but the connections are good. I opened up the switches on the left hand bar and had a look, seems to be clean enough. Put it all back together and it`s still exactly the same. The indicators aren`t original by the way, they`re mini aftermarket ones but they are just bulbs and not LED`s.
It`s as if the engine is stealing the power to the indicators when you start it but the headlight is giving them their power back when you turn it on.
Following advice to check earths, I had another look .
I ran some separate earths from the indicators and the problem is still there. I`ve checked that there is no voltage drop in the live feed and that the battery is receiving charge so the reg/rec seems o.k. I then decided to check the continuity on all earths, so I set the multimeter to continuity buzzer and went to every earthing point in turn, all good. Then I attached the probe directly to the battery negative and went round all the earths again, all good. Out of sheer desperation / frustration / curiosity I started poking at every terminal I could find.
Now then, when I disconnected the switchgear on the indicator side and started to poke at the connector block on the loom, most of the terminals were giving continuity. I pulled the connector off the headlamp bulb and stuck the probe in and I am getting continuity not only to the earth but also to the high beam wire directly from the battery negative. Please correct me if I`m wrong, but doesn`t this prove that there is a breach between the lives and earth??


Now I`m normally not too bad with electrics and can usually find a fault even if I can`t fix it I`ve poked the multimeter into every connector that is in the indicator circuit and checked the earthing as best as possible and can`t find any obvious fault. Am I going mad and missing something that`s staring me in the face???
I`m totally stumped.....HEEELLLLLLPP!!!!