Cessna 400 Series Voltage Regulator Upgrade Kit

[mshac]

Happy Easter Gene! Sounds like you'll have one fine 337.

Regarding charging system upgrades, the paths I'm aware of are fairly limited:

1. Upgrade alternators to 60 amp -
PRO: A) No 337 or POH Change required B) 58% increase in power
CON: A)Expensive! Labor alone will be $1000+ on top of alternator costs B)Stronger alternator puts additional stress on the rubber coupler, which is a very expensive repair when it fails C) Does not fix the unbalanced nature of the charging system so flashing ALT lights in taxi and cruise may not be resolved.

2. Install Cessna 400 Upgrade -
PRO: A)No POH Change required B)Allows alternators to be more efficient by equally balancing the electrical load C) Resolves flashing ALT lights D) Very inexpensive at $499 (by aviation standards at least) E) Installs in 1 hour and any A&P can do it
CON: A) Requires 337 field approval

3. R1224 Upgrade -
PRO: A) Completely updates charging system and eliminates many older components B)Allows alternators to be more efficient by equally balancing the electrical load C) Resolves flashing ALT lights
CON: A) Requires changes to POH B)Ability to re-start alternators in-flight is lost C) Requires field approval and likely a DE D) Costs??? E)Has it ever actually been done???

*Upgrades #1 and #2 may both be installed together

[Learjetter]

Agree that the -400 series regulator upgrade is “1 wire” simple. Checked today and Cessna 337 is on the R1224 approved model list, so you could also go that direction and install them without field approval or STC as a PMA regulator.