[Mark Hislop]

Jazzpilot:

I am familiar with the conversion you are talking about. I got the paperwork from CPA, and had it done to my 73 P337.

There are actually two parts of the converson. The first part consists of replacing the original voltage regulators with regulators from the 400 series Cessnas. These regulators are truly paralleling...they have a sensing lead that connects one to the other, and they always split the load between them. This is the main reason I went with this conversion. You can do this without putting on the 60 amp alternators.

The second part of the conversion consists of replacing the 35 amp alternators with 60 amp alternators. The only change necessary to do this (other than the larger alternator) is a larger gage wire to take the extra current from the alternator to the main bus. I didn't install the larger alternators, since I was a little leery of the extra wear and tear on the engine accessory drive gears. However, I did have a larger gage wire installed in case I ever change my mind.

I have had this conversion done for 4 years now. I've never had to adjust the regulators, and I've never had one of the alternator low voltage lights come on, regardless of my power settings. I used to have continual problems with one or the other alternator going "offline" during flight, as evidenced by the low voltage light coming on.

Mark