Voltage Regulator Failure?

I'd appreciate a second opinion on this one before I purchase a new voltage regulator. (1979 KZ650)

Here's the story:

My bike slowly (over a couple of miles) lost power and finally died on the way home from work. I noticed the oil and neutral lights were out with the ignition on.

Here's the deal: I don't have a manual for the bike to help troubleshoot the problem. On the other hand I used to be an electrician on a submarine, so I've got a pretty good feel for electrical problems.

I put a charge on the battery and it fired right up with the electric starter. In hindsight, maybe this has been a problem for a while, because I've had to kick-start it for a while now.

I've had problems with the bullet connectors in the past, so I checked them. While the engine was off, I checked continuity from the battery to the voltage regulator, and everything was OK.

Next I checked the continuity across the two yellow wires coming off the alternator, and those were good. These should be the armature (output) winding.

Next I started the bike and removed the negative battery cable, and the bike died. This tells me that the charging system is dead and that the bike is draining the battery to run.

Next I checked the output of the alternator going into the voltage regulator at fast idle (about 2000 RPM). The two yellow wires had 22V AC across them, and each had about 10-12 volts to ground.

I disconnected the red voltage regulator output wire and got a reading of only 5.5V DC. This is certainly too low to charge a 12 volt battery.

I don't want to waste time and money, and I think I've pinpointed the problem, which is why I'd like a second opinion on this: Is it fairly certain that the voltage regulator is the problem?

Post edited by: Idaho_Spud, at: 2006/06/17 10:21