Service Tech for Onboard Battery Charger


New Member
Feb 23, 2021
Boat Info
2003 Sundancer 380
Mercruiser Horizon 8.1S V Drives
I have a 2003 Sea Ray Sundancer 380 located at Ft Walton Yacht Club and looking for someone to troubleshoot my ProMariner ProTech 1240I Plus battery charger. Not charging any of the batteries from shore power or generator. I looked for fuses but couldn't locate any. The lights on the Protech onboard charger only come on when I hook up a battery charger straight to the batteries. I have Eagle Extended service protection so it would help if they did warranty work.


That sounds more like a wiring issue than a problem with the charger. You said "only working when connected directly to the batteries". The assumption is then that the charging wires "were" connected through the battery switches? In which case, maybe someone wired them to the wrong post - they should be wired to the supply post otherwise they would only work when the specific selection is made on the switch.

If this isn't the case, please clarify.
I stated that wrong. The onboard battery charger is always hooked up to the batteries. The lights on the onboard battery charger (ProTech 1240i) would not illuminate or charge the batteries from shore power or generator. Nothing on the onboard charger (ProTech 1240i) were ever disconnected. When I hooked up a portable battery charger (EverStart Maxx) the lights on the onboard charger (ProTech 1240i) lit up. I think if was just feeding back into the onboard charger from the portable charger.
OK, got it. Other than checking breakers/fuses to make sure you have good power coming into it and going out of it, I'm not sure. You may want to call Pro Mariner - they've been very good (from my experiences) with helping figure things out like this. They may be able to direct you to an authorized repair service, as well (or send it to them if your warranty covers it). You'll probably have to do the removal, though.
Thanks Lazy Dave. Yes 2 bought last year and 2 bought this year. I was able to charge them up with the portable charger.
Silly you have the "AC Convertor" breaker turned on in your main breaker panel?
Yes I do. I've looked everywhere for fuses but hadn't found any.
Yes I do. I've looked everywhere for fuses but hadn't found any.

I don't think you're going to find any "fuses" on the AC side. It's going to be the breaker in your main panel (AC converter). Pop the bottom or top off the charger and you should be able to easily check for AC coming into the charger.

The 1240I is not a newer ProMariner as far as I can tell. It might be that your charger has given up the ghost...perhaps time for a 1240P.
Thanks, i appreciate the info!
Sea Ray typically installed a circuit breaker for each charger/converter leg to the batteries. It would be odd, however, that all of them tripped. On the 400DA those circuit breakers were behind the main DC disconnect panel in the back of the cockpit. The panel actually had to be unscrewed and pulled out to get to the breakers. Here is a pic from my old 400DA

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