In addition to my daily DR250 hack, I have a 1982 DR500S with 6 Volt electrics I am fixing up - usual stuff, new paint, grease, bearings, and the like.

On the front of the battery cover is a small solid state device (not the indicator switchng device) with two connectors, one of which has bust off. I have no manual. Any idea what it is? A rectifier? Or what? Can I make one, I wonder

Also, there is another solid state device bolted to the headstock - not the large CDI unit, but a small aluminum box thingy - would that be the regulator? It has just one wire and is earthed - as far as I know it works fine (I once made a regulator for a DT175 by stringing together a bunch of diodes wrapped up in foil - and it worked fine).

Any idea how to test these devices - currents / resistance / properties etc? The bike is not ready to run yet but will have a battery and lights as normal when it does.