Onan Generator Control Problem - RC as solution?

[RyanN]

I know this is a different thread, but the forum seems kind of quiet and I have a problem and would love some input.

On our boat, we have a 2001 9kW Onan Marine Genset Generator that is not running. I've narrowed the problem to be a faulty Voltage Regulator. To my understanding of the owner's manual and a short troubleshooting guide from some RV people, the Voltage Regulator does not regulate anything, but actually just shuts the generator down if it has too much current being pulled or of the voltage is too high or too low.

If I force the generator to run (yea... probably a bad idea) the voltage output is 220V, which is what the generator is supposed to output and we have a step down transformer in the engine room. So... the voltage regulator is faulty because the voltage output is correct, and there is not an over current condition.

I looked up voltage regulators online and could not find any marine ones, and the regular RV ones were around $350. Ouch! There is no one to service the generator around anymore since Katrina wiped out most of the marine service places and we are now resorting to an RV place in any help we can get (which is just replacement parts, etc).

I would just plop a new voltage regulator in, but it is hard to get out, and the part that looks to be fried is a diode (which would not catastrophically fail like it did for no reason). So, I don't want to pay $400+ for a new voltage regulator and have it immediately fry again.

The generator model number (or letters in this case) are MKDAL.

Now to the robot controller solution. The generator has horrible ways of indicating what is wrong. The only way I figured what was wrong was by driving 30 miles to the RV place, they gave me some troubleshooting papers, and I found that the reset breaker that kept on tripping to be for an over current condition. It also linked me to the AVR (Which I guess means automatic voltage regulator). There are no large wires going to the AVR, but there are some pretty massive capacitors and what looks to be some transistors attached to a large heat sink buried in the generator.

Now, I had an idea to use a 2005 IFI Robot Controller stuck in autonomous mode to control everything. Then with the program port, send back generator info through the COM port to a linked computer if needed. I would also add some indicator lights to detect low coolant, oil pressure, exhaust temperature, and coolant temperature.

What route would you go? Keep in mind that this generator is buried in the engine room of a boat with two large diesel engines that leave me hardly any room to access the generator, so taking out large parts is a large undertaken (as we would have to pull out the floor).

Thanks for any info regarding what could be wrong with the generator, and I hope to put some more info up later once I get some of the papers off the boat.