Best Replacement For 30 Amp Converter In 1992 Airstream 34'

Updated 02/11/2026 | Published 01/20/2026

Question:

Progressive Dynamics 9300 30 amp or 9300 45 amp? I have a 1992 Airstream 34ft 30 amp. The Univolt under the upfront jacknife couch at the front of the trailer has long seen better days and I am considering a PD3900 replacement. The univolt does not have a control panel of any sort. My question is... Do I go with a PD 9300 30 amp or can I gain anything with a PD 3900 45 amp convertor? I plan to switch to LifePo4 batteries at the same time I install the new convertor. Thanks My 12 volt system is shot and I have to use vehicle jumper cables to take a shower. I am currently working off one 120 volt plug. I have a 30 amp I/O panel at the back of the Airstream where the shore power

asked by: Thomas D

Expert Reply:

Hey Thomas, thanks for reaching out. You will definitely want to stick with a 30 amp when replacing your old 30 amp unit. For that I recommend the following:

- Progressive Dynamics 9300 Series RV Converter Charger - 12V - 30A # PD49RR

There would be no real gain from doing a 45 amp unit. Plus that would require you to run larger gauge wire to the batteries so it wouldn't be as straightforward of a swap.

The # PD49RR is capable of charging lithium batteries so it'll work great once you do that swap.

expert reply by: Jesse M

Progressive Dynamics 9300 Series RV Converter Charger - 12V - 30A
(click to enlarge)

Jesse M.

2/10/2026

Hey Thomas, how did things go with the 30 amp Progressive Dynamics converter in your Airstream? Did it get your 12-volt system back up and running smoothly? Your update could make it easier for others working on similar upgrades.

Thomas D.

2/10/2026

@JesseM The PD9300 took up half the space of the original converter Airstream installed in 1992. Three screws on the flanges, one ground wire set screw and two Allen set screws for the negative and one red for the positive. In the 120 side, I have power showing on the output side of each breaker but, with the exception of one receptacle behind the microwave, all the other receptical have no power. So as soon as I find a 120 wiring diagram and since I am not going to tear off the walls, I am going to disconnect all existing Romex, abandon in place, and wire up exposed and hung fresh Romex, j boxes and receptacles. GFI, of course. Meanwhile, I have a heavy duty extension cord powering the new convertor. Very nice not having to rely on all those dim AA and AAA battery powered lights anymore. I can now actually see what I am trying to do! One note that would make battery type selection on the PD9300veasy-peasy for others: Push the key in ( paperclip style but very thin) AND HOLD IT in until your 12 volt chosen battery type selection color changes.

Jesse M.

2/11/2026

@ThomasD Thomas, thank you for the detailed write-up. That is extremely helpful feedback. It is great to hear the PD9300 fit well and freed up some space compared to the original 1992 Airstream converter. Your install notes about the flanges, ground set screw, and the positive and negative set screws will definitely help other customers planning the same upgrade. On the 120V side, since you are showing power leaving the breakers, that does point toward a downstream wiring or junction issue rather than the converter itself. Your plan to abandon the original Romex in place and run new exposed wiring with proper junction boxes and GFCI protection makes sense. Tearing up walls is not fun. I also really appreciate the tip about holding the battery type selector button in until the LED color changes. That is a great clarification and will help others avoid confusion during setup. Thanks again for taking the time to share your experience, and enjoy finally having proper lighting back in the coach. If anything else comes up as you continue the project, feel free to reach out.

Thomas D.

2/11/2026

@JesseM I secured a 120 wiring diagram for my Airstream. It seems that the entire system is "loopy" in that each receptacle is so wired (punch down type connectors) that it feeds all the downstream plugs. I will open up the microwave receptical and see what gives (or doesn't give in this case! No surprise here that I have a problem after thirty + years of service. Thank you, Jessie, for the assistance. I appreciate Etrailer customer service.