overvolts on G model

[ljmolina]

Originally Posted by mshac

There is only one proven solution - upgrade to true parallel alternators like the 400 series twins. I've sold many of this upgrade to members of this site, with excellent feedback.

Installation requires approximately one hour.

Search this site and you can find detailed info on the upgrade. Or contact me directly at dfwaircraftparts at gmail.com

Cost is $595 deliverd in the CONUS, with tech support included. 30 day money-back guarantee.

True parallel alternators are the solution.

Edit: The exact voltage at which the over voltage light comes on is fully adjustable. Have you verified that it is set at the correct voltage?

I may contact you on this... My rear alternator light intermittently turns off/on

[mshac]

Cessna's Pawnee plant engineers had never designed an electrical system with two alternators. And never would they again! Why they didn't use the proven system the 400 series aircraft uses probably has something to do with "Not Invented Here Syndrome" and rivalry between the two production plants.

Whatever the reason, the dual alternator charging system on our 337's is a Rube Goldberg like design. The alternator electrical outputs are not placed in a parallel circuit where they may be properly managed by the regulators.

The Electrical Upgrade Package includes two used regulators pulled from a 400- series twin ($595 - 30 day warranty through me), or two new regulators from Cessna($1495 - 90 day warranty through Cessna). Also included are specific installation instructions and diagrams, including the addition of the parallel circuit wire. Finally, there is a sample 337 form that has been approved many times by many FSDO's. Your A&P can use it to file the 337 for the upgrade.

Kit installs in about an hour.

Blinking alternator lights will be a thing of the past.

Please let me know if I may be of assistance.

[wslade2]

Will your upgrade work with the zeftronic regulators? (My very first R&R was installing those and already invested in a set. Hate to go backwards to mechanical regulators.) I have low volt front winking at idle, disappears with increased throttle. Also new alternator, wiring and diode.

[mshac]

Originally Posted by wslade2

Will your upgrade work with the zeftronic regulators? (My very first R&R was installing those and already invested in a set. Hate to go backwards to mechanical regulators.) I have low volt front winking at idle, disappears with increased throttle. Also new alternator, wiring and diode.

Unfortunately it will not. The regulators must be designed to use the parallel circuit.

My understanding is that Zeftronics produces voltage regulators that incorporate the parallel circuit (that is so critical to balanced charging), but they would require a 337 field approval as well.

That fact that my system is basically copied from other certified twin Cessnas probably makes the 337 approval process a little easier. YMMV.

[Kim Geyer]

Check your over voltage sensor. I had one of our planes doing that and found a corroded pin

[wslade2]

Gotchya. I'm expecting it's corrosion somewhere and have been on the hunt for it when not dealing with other issues.

[sunnysky]

Just to let all out there know , I have resolved my overvolts issue.
The rear alternator was faulty . We found chaffed wires in it.
So , replaced it with a new Plane Power alternator at great expense ( we are in Europe)
Also replaced the diode on circuit board that sits on bulkhead in front engine compartment ,
In fact we replaced both front and rear diodes .(only cheap, even here)
System now works normally.
Hope this may be useful to others out there.