Community Forums

oildriller83 · 07-09-2016, 01:48 PM

We've had our 97 Pace Arrow Vision for three years now. No real issues other than problems I've created.....until last weekend. We took it out for the second time this year, and the batteries died on the first day, while plugged into shore power. The coach batteries never showed charging (didn't have a volt meter on me, had to go by display over stove) on shore power or generator (while running the gen, I honestly didn't give it much time). The kicker, when I would start the engine, the alternator would immediately brighten the lights and start charging the system.

After returning home, I was convinced my 110v-12dvc inverter was bad. So, I tear into everything and pull it out. Before ordering a new one, I got the bright idea to test it. Out showed 13.8dcv coming out. I've hooked everything back up and now on shore or gen power, the inverter still shows 13.4dcv (everything running that can be to pull a load) at the inverter and 12.9dcv off the batteries....is this about the right volts, any ideas what's going on?

Skip426 · 07-09-2016, 05:08 PM

Could you post some info from the unit you removed and tested .
Make , model and amp rating. Should be a sticker on it.
I believe, from the year of your coach, that it will only be a converter/charger , not an inverter .
Output from the C/C at 13.8 v sounds ok , some would go as high as 14.2 then cycle down to 13.1 for maintenance of the batteries state of charge.
13.4 under load is probably ok but that depends on the units rating in amps.

oildriller83 · 07-09-2016, 05:52 PM

I'll have to get the info off the sticker, the 13.4 under load I believe is perfect, but the batteries are showing 12.9 under load as well.....is that three reading they're supposed to have while being charged?

oildriller83 · 07-09-2016, 05:54 PM

I have this currently on my phone. The output is perfect according to the stickers. I just can't figure out why the batteries went dead and wouldn't charge without the motor/alternator running

jelag · 07-10-2016, 05:47 PM

First... an inverter changes 12VDC to 120VAC while a converter changes 120VAC to 12VDC....

In most cases a motor coach has a master control system... it gives the gen set priority when it starts and runs... and when the gen set is off... allows the unit to be powered by shore power.... once the master control system gives one device or the other the priority than the converter is powered up and the batteries are charged..

If you find that with either shore power, or on the gen set... you have the 13.8v out of the converter than these circuits are working correctly... one more thought... the alternator runs to a set of diodes.... one set sends power to the chassis batteries, and the other set runs power to the coach batteries... these diodes are called isolation diodes and are usually close to the alternator and the size of this device is based on the output of the alternator... this system is always separate and always functions unless the alternator is not functioning...

So if we go back to the 13.8vdc out of the converter.... between this converter and the coach batteries... is a master fuse... on my converter its IN THE CONVERTER... on my old unit it was a large fuse in the area of the coach batteries and tied in at that location... based on the output rating of the converter... the fuse protects that system... thus a 40 amp converter might have a 50 amp fuse... some systems have (2) large fuses in parallel....

SO I ASSUME both your gen set and shore power, will power up the converter... and it has output... follow the output wires from the device to the batteries.... you'll discover the fuse..

mus289 · 07-10-2016, 09:33 PM

If your coach batteries are more than 4-5 yrs old with the symptoms you are explaining and converter is testing fine your batteries may be toast. I ran into this a few months back. While camping with 50 AMP service the 12V lighting would occasionally flicker and dim, then get better. And you could tell vent fans rpm were also off of normal. My charge monitor was dropping down to 11volts so I also initially thought converter was culprit. Long story short, I eventually figured out that the 2 coach batteries would not carry enough load any longer so even plugged into 115volts the cells were bad enough they weren't transferring full voltage any more. The previous owner of my rig had replaced batteries so I knew they were at least 4 yrs old. Once replaced all problems solved. I know they are a pain to get to, but see if your local auto parts store can load test your batteries if you bring them in? My two cents worth! Good Luck!