I'm slowly reassembling my EA81 1990 Brumby and swapped in a combination light switch from a 1986 GL model.  It had 6 wires in the plug, mine had 5. 

 

I thought I had rewired and pinned everything correctly since all of the lights work (except dash lights).  Using my multimeter ive found 2 live wires into the switch, then one circuit for park lights, one for headlamps, one for tail lamps and one for dash illumination lights.

 

But heres where the problems start....  With the tail lights on or brake lights active, the temp gauge starts climbing.  Using the turn signal on either side causes both indicators on the gauge cluster to flash.

 

So ive clearly cocked something up here.  Any advice or diagrams would be greatly appreciated.  This thing is pretty stripped out and runs the absolute bare minimum equipment....so it should be simple enough to figure out.  I think I might have used the 2 power feeds the wrong way around and so the current draw for the tail lights is coming from the same circuit as the instruments.  But its also possible the massive cut section of loom where the heater/radio used to be is needed for something.

Edited January 19, 201412 yr by keltik

Don't know if this will help or not, this is the 84-87 diagram for the Brat.

A little overlap.

 

Power supply routing 84-87 don't have any 90' stuff

Figured out the wonky electrics.  There is a ground wire from the instrument cluster that runs to the LH/passenger side of the dash then loops back across to the drivers side grounding point.  This wire was broken on mine.  Thanks for the diagrams, they helped me get the new light switch working a treat.

 

Now i have a small issue of voltage drop on the accessory line, but theres plenty of info on here about how to fix that.

Awesome, glad they helped.