Confused on light bulb voltage?

[zerocool420]

I have a 85 vmax and the speedometer lights and water temp light bulbs are blown out. The headlight and tail light still works. I have checked for dc voltage at the speedometer bulb socket and it shows like .6. If i check it with ac voltage it ranges from 12-13 all the way up to 32 with higher rpms. So im confused, are the lights suppost to be fed by ac or dc voltage. If its suppost to be dc, then how does the voltage regulator work with only one wire going into it? I also checked the ohms at the lighting coil according to the manual and its like .11 and the book says no more than .6, so is the lighting coil bad. Im lost because the headlight and tail light are still working properly. Any one with any insite into this problems would be greatly appreciated, thanks!!

[Vmax540]

Lighting on sleds will be AC current and DC is used if there is a battery to charge. The AC voltage should rise with the throttle but I would not think higher than ~14.5 volts. Sounds like your voltage regulator on the front of the left foot well ( below your secondary) has gone bad or is loosing ground ? Clean your ground & mounting bolts then recheck voltage. Let me know and I can ship you one out for the price of shipping. Your coil readings should be taken at ~ room temp.
http://www.vintagevmax.com/1986_service.htm
Lighting Coil Color Code/ Resistance/ Output Yellow~ Black/ 0.25 Ohms +/-10%/

[zerocool420]

Ok well I think ive got it figured out. The voltage regulator had a break in the wire so I fixed it and now the ac voltage to the light sockets is about 11.5 at idle and 12.8 or so with rpm. I replaced all the bulbs and now they all work correctly, thanks for the info, I really appreciate it!!