Just a curious little insert in a wire under the dash, red/orange wire on the lighting (mainly) plug a voltage regulator or restrictor. I thought it was the fog lamp wire at first but its not.

 

That's a diode; a one-way valve for electric current.

On Series III cars red/orange is part of the license lamp/marker lamp circuit. I suspect the same for a Series II. Not sure why a diode would be there. I suspect part of an alarm installation?

Cheers
DD

 

What messy solder work! Hope those junctions were properly insulated.

 

very globby eh, yes lots of insulation on them.

 

yeah i cant figure what it is supposed to be directing power one way too. nothing obvious jumps out when tracing the leads.

 

I believe the gauges supplied by the regulated 10V DC are the Oil pressure, Coolant Temperature and perhaps the Fuel tank gauge. The Voltmeter I think is from battery/Alternator supply. That would give you the 3 leads needed. I cannot be certain, as my S57 diagrams does not show any sign of a 10V regulator, but it makes sense to have a constant regulated voltage feeding those 3 particular gauges.

 

Oh, hit the wrong thread - meant to send it to the 3 wire gauge thread!

 

the Turn signal bulb wires at the tachometer have a similar diode about 3 inches away from the bulb socket, wrapped in tape.