Temp gauge not working.
Oil light not working.
Alternator light not working.
Electronic cooling controller not working correctly
I verified that the temp gauge it's self was working first, then i identified the sensor on the engine block, remember this is an air cooled engine so the gauge reads engine head temperature from a sensor directly in one of the cylinder heads.
There are two more similar sensors the signal a control box that controls the oil clutch of the engine cooling fan. The control box also monitors oil temperature
A simple test is to remove the wire from the sensor and short it to earth, the gauge should move to max, It didn't.
So i started tracing the wire from the gauge to the sensor, i used a tone sender that is used in the telecoms world, after a lot of dismantling and loom stripping i finally found the wire i was looking for, of course it changed colour twice just to confuse me. But i finally tracked it down, it was at the back of the engine instead of the front where it should be, just taped up in a loom not connected to anything. It took me the whole day to sort this one out.
Loom stripped to reveal the elusive wire.