My converter in my '95 Sunnybrook TT has started intermittent humming and the lights are dimming. Based on what I've read, this means the converter is probably going bad. Correct?I have a MagneTek 3240 unit. I have never replaced one or worked on one, other than checking fuses. This unit sits in a plywood stand under the sofa. Removing the sofa will make it very accessible.What replacement unit should I consider? It is a 40 amp unit. I would think I would want a smart charger in the new unit.Thanks.

Yes, more than likely, a bad converter. You will probably want to assess the health of your battery at the time you replace the converter. Any auto parts store will load test the battery.I have a Progressive Dynamics converter. It is 44 years old and still working fine. I have no other recommendation. If you contact Best Converters and ask to speak to Randy, he will give you the model # and pricing on a converter replacement that won't involve replacing the distribution center. Good luck with your 12V issues. I would replace that Magnetek sooner rather than later. It may be stressing things connected to 12 V.

I replaced mine with a Progressive unit with the charge wizard. The folks at Best Converter can tell you what should fit.

westend wrote:Yes, more than likely, a bad converter. You will probably want to assess the health of your battery at the time you replace the converter. Any auto parts store will load test the battery.I have a Progressive Dynamics converter. It is 44 years old and still working fine. I have no other recommendation. If you contact Best Converters and ask to speak to Randy, he will give you the model # and pricing on a converter replacement that won't involve replacing the distribution center. Good luck with your 12V issues. I would replace that Magnetek sooner rather than later. It may be stressing things connected to 12 V.Many thanks to you and GrandpaKip for the help. I will check with Best Converters.I'm keeping my fingers crossed, as DW and I are headed out tomorrow for a weekend getaway. I do keep my battery switch turned off most of the time, just occasionally charging it with the converter. So hopefully no problems there. I will make sure the battery is charged good with my charger before our trip (my TV charges going down the road, too, if I have the battery switch turned on). If the converter failed completely, the fridge and water pump, and a light or two, will need that power. I can run our ceramic heater off an extension cord. The state park we're going to has 20/30/50 amp at each site, but no water. So I need the pump.

This brings up a question...is there a fuse I can pull to isolate the converter from the 120v power? In other words, can I have the TT plugged into the pedestal and have my receptacles work, but have the converter disconnected so it is not causing me a problem?It would be nice to run 12v items off the battery, but still have use of the 120v outlets.

Humming and dim lights may be result of shorted cell in the battery due to over charging using the single mode 13.6VDC Maganetek converter/charger. They are known to do this over time. Need to check the battery fluids and if it is dry you probably should replace the battery. Once they boil out and short internally it is very rare they come back to life for you.I haven't looked up the Magnatek unit but you may not have to do anything with the Power Distribution part of it. Just change out the converter/charger unit mounted in the bottom compartment. This will only require you to hookup the 120VAC side and two or three large battery cables... Mr Randy will tell you what units will fit in the bottom compartment of your unit.I have the PD9260C smart mode converter/charger unit here charging up to four 12VDC batteries. After changing out my 45 Amp WFCO WF8945 that would never go into in smart mode charging I never any had more issues with the batteries. I still check the fluids however on a scheduled basis mostly out of habit. I would go for the 45AMPS model or even the 55 amp model if you think you might ever add a second battery later on. Progressive Dynamics smart mode units are excellent converter/chargers with great track record. Each battery you have in your setup will need 17-20AMPS of DC Charge if you want to re-charge them to a 90% charge state in a quick three hour time frame. Almost all of the public places we go to here on the East side has generator run time restrictions in place so we need to charge up the batteries to their 90% charge state as quick as possible. Then we are good for the next day/night camping run off the batteries. I got mine from AMAZON a saved a couple of dollars that BEST CONVERTERs was offering. Mr Randy is well known among the RV'ers... A great guy... Having said that don't let him talk you into a WFCO WF8900 series smart mode converter/charger... Almost everyone has problems with that brand going into smart mode charging when you need them to do it...Progressive Dynamics or the IOTA models are very popular amoung the RV'ers...Roy Ken

MagneTek 3240 replacement | Good Sam Community

XxOKIExX
Explorer
Mar 22, 2016
shot in the dark, but Fallsrider, any chance you can send me the completed pics. They are no longer displayed in the thread.

I'm doing the same thing and would love to see the finished product. Mainly in regards to how you treated the Positive and negative leads from the battery and converter when you tied in the external fuse panel.

Thanks
fallsrider
Explorer
Nov 23, 2015
opnspaces wrote:
Hey Fallsrider I have a question. I was looking at the boondocker on Bestconverter and it mentioned 15 amp 3 prong power plug on all models. Did your trailer have a plug for the power to the converter, or did you just cut the plug and wire it into the existing wires?
Yes, my trailer has a receptacle next to the converter dedicated to it. No wiring was necessary.
opnspaces
Navigator II
Nov 23, 2015
Hey Fallsrider I have a question. I was looking at the boondocker on Bestconverter and it mentioned 15 amp 3 prong power plug on all models. Did your trailer have a plug for the power to the converter, or did you just cut the plug and wire it into the existing wires?
fallsrider
Explorer
Nov 20, 2015
My fuse block came today, so I was able to install the new converter this afternoon.

Old converter after removing the wires from it:

New converter after being wired up:

Fuse block:

Since the new converter had a lug for it, I installed the chassis ground to it. Do I need to run a chassis ground over to the fuse block? It is grounded with the negative wire, but I don't know if it should also have a chassis ground.

My trailer must be at least 5 lbs. lighter now. The old converter was much heavier than the new one. The new converter is completely silent, as I did not put very much load on it. The battery is showing 13.28v with the battery switch on. The battery was almost completely charged, so the converter may not apply any higher voltage until it is drawn down some at a future date.

Is it pretty much a consensus that these new converters should be allowed to charge the battery at all times since they will go into maintenance mode for a charged battery?
fallsrider
Explorer
Nov 14, 2015
Yeah, if I had really thought it through better before ordering, I would have realized that the individual circuit fuses are inside the front of the old converter, and had I remembered this, I might have questioned Randy about it.

But it is not a big deal. We don't have any trips planned, and I winterized this week anyway. I do camp occasionally during the winter months, but not over the next couple of weeks. I just have to delay my tinkering! I've got a fridge problem that needs some more work anyway. That will give me something to do.
CavemanCharlie
Explorer III
Nov 14, 2015
fallsrider wrote:
I'm a little bummed this evening, but I'll get over it. My new PowerMax Boondocker converter arrived today as scheduled. I took it out to the TT and started looking it over and determining what I had to do to switch them out.

It became apparent to me that I have a problem. My old MagneTek came with an integrated fuse block. In other words, when I remove the old converter, all the connections and fuses for each 12v circuit go with it. Apparently, some MagneTeks came with the integrated fuse block, and some didn't. Randy at Best Converter says he didn't realize I had one of the integrated types, and I'm sure he didn't think to ask. And I didn't know to ask as this is the first time I have ever messed with a converter.

Bottom line is that Best Converter has a fuse block just for this situation, but with shipping it is another $43 I hadn't counted on, and I have to wait several more days for it to arrive. I'm just not going to pay for any shipping more expensive than ground.

I would have had to buy the fuse block anyway, but I wish I had known when I ordered the converter and I would have included it then! Oh, well, it could be worse.

Sorry to hear of your bad luck . But, thanks for posting this on here for others to learn from.
fallsrider
Explorer
Nov 14, 2015
I'm a little bummed this evening, but I'll get over it. My new PowerMax Boondocker converter arrived today as scheduled. I took it out to the TT and started looking it over and determining what I had to do to switch them out.

It became apparent to me that I have a problem. My old MagneTek came with an integrated fuse block. In other words, when I remove the old converter, all the connections and fuses for each 12v circuit go with it. Apparently, some MagneTeks came with the integrated fuse block, and some didn't. Randy at Best Converter says he didn't realize I had one of the integrated types, and I'm sure he didn't think to ask. And I didn't know to ask as this is the first time I have ever messed with a converter.

Bottom line is that Best Converter has a fuse block just for this situation, but with shipping it is another $43 I hadn't counted on, and I have to wait several more days for it to arrive. I'm just not going to pay for any shipping more expensive than ground.

I would have had to buy the fuse block anyway, but I wish I had known when I ordered the converter and I would have included it then! Oh, well, it could be worse.
fallsrider
Explorer
Nov 10, 2015
westend wrote:
....BTW, installation time is a good time to upgrade charge circuit wiring. Nearly all TT's are built with barely adequate wire in that regard. I'd suggest AWG 4 (and make that welding cable if easily available)....
I looked into this, and my TT's charging circuitry has AWG 8. I see that is rated for 40 amps. If we dry camped a lot with a lot of battery usage, I would consider upgrading the wiring. However, we do no dry camping at all, and the battery just gets topped off and maintained from time to time. My battery is only a Group 24. We don't have any plans anytime soon to change our camping style, either.

Fortunately, the wires are easy to get to, and if I ever see the need to upgrade, it won't be a big deal. But thanks for the suggestion anyway!
fallsrider
Explorer
Nov 07, 2015
This afternoon I shut off the battery and turned the converter back on. Within minutes, my DW turned on the water and when the pump kicked on, the converter clicked and started humming continuously. I shut off the pump and the couple of lights that were on and the humming would not stop. I think the converter is now dead.

I killed the breaker and turned the battery back on. I also hooked up the charger. It is charging now. Thankfully, we don't have any planned trips to worry about before I can get the new converter installed.

Thanks for the tip on the charging line. I will look into that.
westend
Explorer
Nov 07, 2015
fallsrider wrote:
Right or wrong, I ordered the Boondocker converter this morning. The reviews for both units are very positive and the Boondocker has one year more warranty. As westend said, I probably can't go wrong either way.

My converter is acting up on our trip, so right now we're operating on 120v and the battery. I have the converter shut down. Everything is working well this way.

I know you keep an eye on battery SOC but, if you brought along your battery charger and have 120V available, plug that sucker in. I'd hate to see you have a battery issue with your new converter.

BTW, installation time is a good time to upgrade charge circuit wiring. Nearly all TT's are built with barely adequate wire in that regard. I'd suggest AWG 4 (and make that welding cable if easily available).

Good luck with the new Boondocker! A few Forum members have them and are posting their results when in use. All look like good reports.