[Mark Hislop]

Allen:

I have had this problem, and from what I've heard, it is not uncommon. There are at least two "generic" causes. One is that the regulators are swapping the load back and forth, and the other is resistance in the field circuits which causes the regulators to "hunt"

I had both problems. My regulators were boucing back and forth, and not sharing the load equally. Many people maintain that keeping the electrical system in good shape (as detailed by Bob Cook) will keep the system working properly, and probably they are right. The other thing you can do is get a Form 337 from CPA that will allow you to replace the existing voltage regulators with regulators from 400series Cessnas that are truly "paralleled". I have done this on mine (as well as replacing the diodes and capacitors) and my alternators have shared the load flawlessly for the last 4 years.

If you turn off one alternator (thus there is no question of the regulators bouncing back and forth between each other) and the lights still flicker, your problem is probably one of some extra resistance in the field circuit. This causes the regulator to constantly hunt, and the voltage changes are what causes the lights to flicker. Check any connections in the master or field circuitry, and check the master and alternator switches. You may have to put new connectors on the wire ends. The least little bit of resistance can cause this problem. I had to change out my master switch, even though a quality digital ohm meter showed it was good.

Mark