Converters 2, me 0 - Montana Owners Club

rldriver · 02-07-2005, 11:19 AM

So am I the only one with converter problems? Picked up my 2005 2955RL brought it home and thought it was strange that after hooking it up to 110 vac I noticed that the battery was at only 1/3 capacity. Checked the converter and both 30 amp fuses blown. Installed new fuses and nothing. No power to the battery, 11.5 volts. Back to dealer and they changed out the converter. It was working there, putting out over 13 volts to the battery and was running all 12 volt systems. Good, now we can take our first trip.

Brought it back home and hooked it up to 120 vac and no output to the battery, checked the fuses and they are good. Put about a 4 hour charge on the battery and went camping. Hooked up to 50 amp service and when we got up Saturday morning we had no 12 volt power so the refrigerator quit on us. Checked the battery, 9.5 volt, so I hooked up my battery charger and we had a wonderfull time for the rest of the weekend. The charger finally brought the battery up to full strength and also ran the 12-volt system just fine. As I am writing this our rig is back at the dealer to see what they can find. Any thoughts out there?

rames14 · 02-07-2005, 11:40 AM

I am sure that people will jump on this quick. But, it sounds like the charger portion is not working or you had a bad battery. But since the charger brought it back up to 13V, that is unlikely. Did you by any chance put a meter on the lines coming to the battery from the charger? You should have gotten a "trickle" charge coming through the lines to the battery. Make sure your dealer checks all of that out. Best of luck.

Dave e Victoria · 02-07-2005, 12:06 PM

I'd be tempted to look for an intermittent or open circuit between the battery and convertor. Could be as simple as a piece of wire insulation trapped under a cable terminal. Many convertors are subject to self distruction if not connected to a battery even for a short time

Charlie · 02-07-2005, 02:17 PM

This may sound too simple but check connections on the terminals, had a similar situation and found the wing nut on the positive terminal loose, don't how it mangaged to work its way loose.

Montana_657 · 02-07-2005, 02:42 PM

Modern converters are very reliable and not prone to self destruct. As you have a 2005 I assume you have a very modern converter. First of all you need a digital meter to measure battery voltage. About 13 volts isn't good enough. My converter floats at exactly 13.8Volts... read your manual... measure accuractly and see what is happening exactly.

If you were useing an old style brute force type battery charger... I would suspect the high frequency garbage it puts out has either fried or at best confused you converter.

Considering my old 2003 model has a converter capable of 50 amps I really wonder how you managed to have a 30 amp fuse in the chargeing system. I would expect to find it blown. You have a warrenty... best use it. Your dealer will be paid to make this work for you. No need to troubleshoot this on your own.

Montana_2785 · 02-07-2005, 11:32 PM

FWIW: My "new" 2002 3575RL also is having converter problems. Haven't had my meat hooks on it long enough to figure out what is wrong... I also have to use a battery charger to supply 12V for now.

Eric

lightningjack11 · 02-08-2005, 02:59 AM

I am not familiar with the new converters but I used to have a problem like this and solved it.

On mine I have a row of DC terminals that receives DC power from the converter electronics when connected to shore power and switches to Battery when not connected.

In addition I have 3 ACC DC terminals that are directly powered by the battery. When connected you get a trickle charge on the line. I think these are primarily for suppling filted DC for applications requiring low noise power.

My problem was that when my heater fan was running it would discharge the battery at rapid rate. Upon close inspection I found that the heater had been miswired to the ACC terminals. The trickle charge could not keep up with current draw from the heater fan. Don't put any high current lines on these terminals.

Moving the heater wire to one of the main DC connections solved the problem. The converter can keep up with load but the trickle charger cannot.

I don't know it this applies to the newer converters but I thought I would at least tell you.

Like Gruffy said make sure you have 13.8 when connected to shore power or when connected to the truck with it running.

------------
Another common problem I will mention is that the charging circuit goes through a large power resistor that sometimes opens. The resistor is inside the converter in the back. On mine I discovered a bad solder joint on the resistor. This is caused by heat generated by current and bad solder techniques. You won't get 13.8v if this occurs.

sreigle · 02-08-2005, 04:08 AM

Wow, great info, Tom!

One of the replies above triggered a question in my mind. Is there any problem with connecting an external charger to recharge the battery while the battery is still connected to the converter which, in turn, is attached to shore power?

I saw a comment above that having the battery disconnected from the converter when attached to shore power can create a problem for the converter. I also saw above that charging the battery from an external source while the battery is attached to the converter can confuse and create a problem for the converter.

As fulltimers we're always hooked up to shore power except when on the road. If I check the battery and find it's low on water and needs a charge, am I going to hurt anything if I refill with water and hook up my battery charger without disconnecting either the battery or the shore power?

Thanks.

Montana_883 · 02-08-2005, 05:03 AM

Had a similar problem. It ended up just what Charlie said...The battery terminals were loose. The nut was tight but a burr on the post thread was not letting it tighten up. Hope you find your problem, good luck.

rldriver · 02-08-2005, 05:22 AM

Thanks to all for your ideas. It is at the dealer now for the 2nd time in as many weeks. I did not use the battery charger until I discovered that the converter was not working. I needed to run the refer. and the controls take 12 volts so will not operate on 110 vac without a 12 volt supply. I think they designed the controls to work on 12 vdc so you could run it on propane with out shore power. Yes, it's a new converter with 2 30 amp fuses. It is still under warranty as it is only a week old but the dealer could have a problem finding the problem as when they determined that the first one was not working they installed the second and it was working fine when they had it hooked up to shore power at the shop. Got home and it was not working, very interesting. Yes we checked the output of the truck and it was working fine.

trukdoc · 02-08-2005, 12:38 PM

I may be barking up the wrong tree but I am going to mention this anyway.
Has the polarity on the AC plug been checked? Most AC appliances are not sensitive to polarity....some are!

Montana_657 · 02-08-2005, 01:48 PM

So.. what's different at home??? Do you have a 30 amp or 50 amp RV power plug or do you use some sort of adapter??? Is your household wiring correct??

Just a couple of things to check. Hope it helps.

rldriver · 02-09-2005, 12:13 PM

Quote:

quote:Originally posted by Gruffy

So.. what's different at home??? Do you have a 30 amp or 50 amp RV power plug or do you use some sort of adapter??? Is your household wiring correct??

Just a couple of things to check. Hope it helps.

Thanks Gruffy I will check out my house wiring. I think I have located my problem. Don't tell but

(egg on face) I may have shut off the circut breaker for the converter when I got home the second time around. It was hand written and I could have misread it as dryer, will pick up unit on Thursday and check it out. Dealer said it was working fine at the shop.

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