Voltmeter and clock pod mounting brackets attachme

[Dizerens5]

In case of interest, the German VDO company makes a voltmeter for light aircraft instrument panel. It is accurate and has the usual 52 mm fitting so will fit brackets like those from British company Vehicle Wiring Products. I had one on my Ural for several years. It didn't object to rain.
I checked my BMW voltmeter against a digital multimeter. It proved to be accurate with lights off, but oddly enough reads 4-5 volts too low with headlight on. As you say, this sounds like a connection in the wrong place. My R65 is 1979 and does not have a specific connection for the pods. Someone has connected the clock direct to a battery terminal (with fuse). I haven't yet located the voltmeter connection but I will. Both dial lights had been removed and wiring cut off for some reason - I had to reactivate them (by bullet connectors off the parking light).