Two years ago I had to fit a new Voltage Regulator to my C182Q replacing the old original unit with 30+ years of service on it. The failure was due to water ingress. The new regulator is a Lamar DGR3-1 unit and now with <200 hours it has failed. It’s not wet but it has failed. There is no voltage going to the alternator exiter coils.
I know there is a wealth of experience on here so can anyone suggest why this new unit has failed so quickly. Might there be other contributing problem. Then the big question is do I replace it with the same or try a different manufacturer like the Zeftronic’s equivalent. Being a Cessna everything is STC’d appropriately so I have options.
Viewpoints appreciated.
Can’t really help but say that these voltage regulators are defnintely a weak spot in out spamcan aircraft. This is true for old (>20 year old) voltage regulators mostly, but as you say, even “new” ones just fail.
Most of the times when one reads about aircraft going tech on “trips”, it turns out to be a bad regulator.
These new solid state style regulators normally are quite ok. Does the regulator gets voltage input? The over voltage protection is between the FIELD circuitbreaker and the regulator, and sometimes go bad as well. If you regulator doesn’t get input, it can’t work either. Do note that the OVER voltage, or UNDER voltage light will come on as well. The design of this light is that it sense if the regulator gets input voltage or not.
So dead regulator, but voltage on it’s input, will show the high / low voltage off, indicating that the system should work, it doesn’t monitor the output voltage of the alternator.
Be sure to check the field wire as well, short circuit the field wire will kill the regulator.
Thanks for the feedback. I’m much more knowledgeable now. I found a superb article in Cessna Pilots Association and spent this morning going through everything. It turns out it’s the alternator that is probably faulty, the ACU seems to be OK and passes all the tests. I was wrong about the lack of field wire voltage it is OK.
I’ve checked all the wiring all the way from the battery and I’ve checked the battery earth for voltage drop and everything is OK. There is a 0.5V drop from the battery to the ACU supply but I think that is OK considering the battery is in the tail.
I had noticed interference on my headset which is a tell tale of diode problems in the alternator apparently.
I’m going to replace both the alternator and the ACU. The ACU is the standard Lamar unit which I’ll replace with a Zeftronic’s unit. As for the alternator, I don’t know. Plane Power seem to have a good name. Any suggestions?
Plane Power has been bought by Hartzell/kelly = CRAP.
Plane Power used to be the best option. Maybe they can beat the odds and keep it good even under the Kelly brand…
Rumours is that subcontractors earlier providing Plane Power with parts for their Alternators has refused to continue so under the Kelly brand name….
BWTHDIK
Just get your excisting Cessna alternator (if you have these) overhauled. They can be almost endlessly repaired / overhauled / serviced.
The plane power units have been designed to last as long as the engine TBO, however they don’t always make this.
I would recommend a 500 hours on all alternators whatever the supplier says. Excessive wear on brushes and bearings will cause damage and make it more expensive on the long run.
Jesse,
Do you have any recommendations for such OH in Europe?
Just the question I want to ask! Who overhauls alternators in Europe. Mine is a 60amp Ford unit.
Most shops do that I would say. It’s trivial.
They can change the brushes, sure 
