No DC power with fully charged batteries

ksandbothe · May 19, 2016, 12:24 PM

1989 Winnebago Warrior 27eu (Class A.) Chevy 454 P30 chassis.

We have fully charged house batteries but no power to the 12V lights, etc. They 12V lights, etc., work with shore power and with the generator. We checked the breakers and fuses in the panel located below our refrigerator. Online searches indicate that there may be 5 amp battery in-line fuses, or a circuit breaker/fuse for the converter. We have spent two days looking for ANYTHING that resembles these. Any idea where to look? Or even if we would have them on a 1989?

The voltage readings on the chassis batteries do not change when plugged into shore power or with the "dual" switch when the engine is running. We assume this means the power is not reaching the chassis, and the charge is not reaching the house batteries.

We are to the point we are thinking the converter needs replaced.

legomybago · May 19, 2016, 01:13 PM

"We have fully charged house batteries but no power to the 12V lights, etc. They 12V lights, etc., work with shore power and with the generator."
Sounds like your convertor is working just fine
"The voltage readings on the chassis batteries do not change when plugged into shore power or with the "dual" switch when the engine is running. We assume this means the power is not reaching the chassis, and the charge is not reaching the house batteries."
You need to find the battery "kill" or disconnect switch is what it sounds like to me?

ksandbothe · May 19, 2016, 01:26 PM

We know where the "disconnect" switch is on the dash. On ours the "dual" / "auxillary" switch is the disconnect switch when in the neutral position. We don't actually hear any clicking sound when switching between modes.

We have traced a red wire from the chassis batteries to a solenoid (?) in the front of the vehicle, but we haven't found any breakers or fuses.

Rickf1985 · May 19, 2016, 01:45 PM

The dual/ aux switch is what connects the chassis battery to the house batteries. What you need to find is another switch that shuts off all battery power to the coach. Mine has a red light next to it which is on as long as the batteries are on. On my 89 Chieftain that switch is to the left of the radio in the dash. My Dual/aux switch is to the left of the steering column.
This is the one that turns everything on and off.

Rickf1985 · May 19, 2016, 02:00 PM

Here is a better view of that switch area and also a shot of the dual/Mom or aux switch. My switch has been changed so the position may be different as far as how it is positioned on/off.

DaveVA78Chieftain · May 19, 2016, 09:13 PM

This problem can either be a battery disconnect solenoid or the transfer relay in the Magnetek 6300 series converter (top right in the following schematic). It determines if 12VDC source is from the battery or the converter.

The relay is the white block in the bottom right of this picture

Rickf1985 · May 19, 2016, 09:18 PM

I am thinking battery disconnect because even when they hit the MOM it does not change the voltage in the coach battery. Completely isolated. I am thinking they are not hitting the battery disconnect switch since they are only mentioning the MOM/aux switch.

87Itasca · May 20, 2016, 09:39 AM

Mine had the same problem as you are having. I replaced the Battery Disconnect Solenoid, and it fixed all my 12V problems. I heard the "thunk" noise it made when I switched from DUAL to NORM and MOM, but it wasn't actually latching internally. I only caught it because after doing it enough times, I saw the green "AUX BATTERY" light on extremely dimly. When it was on, I had 2.9V at my power panel. As soon as I turned on anything with a 12V load, it dropped to zero.

http://www.amazon.com/Intellitec-Battery-Disconnect-Relay-Prevents-Batteries/dp/B00KPR8QAO

HamRad Mobile · May 22, 2016, 03:52 PM

Good morning, ksandbothe;

I just lost the written reply for the second time, and this third attempt will be the last for today. One advantage of this problem is that this will be a greatly abbreviated version.

I have a 1987 Winnebago Elandan WCP31RT which also had the Magnatek or B-W 6345 RV 12 VDC "power converter" in it. I also agree with others that you may be experiencing a problem with the "change over relay" inside the 6345.

My cure was not to replace the relay, but instead to replace the entire B-W 6345 "power converter. There is a reason for this decision.

One almost unknown problem with the earlier design of the RV 12 VDC "power converter" is that it is just the first half of a real power supply, and it does not have any filtering nor regulation built into it. The power it provides is not a smooth straight steady voltage level like we expect from a battery, even though it does say that it is a "12 VDC" device. They are playing with words and definitions here.

If you read the instructions found with some of the "power converters," at least they are honest enough with us to tell us to use a "True RMS Reading" DVM or Digital Voltmeter when measuring the "power converter" output voltage, but they do not tell us why. There is a reason for that, and it is because the output is not a steady single DC voltage level that we would normally expect to see, like from a battery. Instead, it is a "full wave rectified pulsating direct current" waveform right straight off the rectifiers following the center-tapped secondary winding of the transformer.

The voltage that you will see on that waveform ranges from the Zero (0) volts level rising up to a peak of right about 18 Volts as it turns and starts to fall back down to Zero volts again when it repeats the cycle again; it "pulsates."

It is that 18 volt peak that is the unfortunate kicker for us. That is what was causing the early death of my LED lights I was putting into the Elandan. And when I told the guy who sold me the LED lighting replacements, he flat told me that I was running them on too high a voltage. I replied that I had measured it with the DVM I carry in the motor home. Later I remembered about that "true RMS reading" thing, and I got out the oscilloscope to look at the waveform. Yup, a simple full wave pulsating DC waveform, just like in any basic textbook covering linear power supplies. Boy, was I disappointed.

Back in the 1960s when that 12 VDC "power converter" was designed, the main things that were operated off the 12 VDC electrical power circuit were the incandescent light bulbs, the water pump, some simple control boards for the refrigerator and the heaters, and some fans for moving the air around. They worked fine in that application. However, our use of electronics devices has greatly expanded to include color televisions, GPS navigation systems, cellular telephones, computers, printers, special sound systems, and many other things, along with the chargers for recharging their batteries. Those things are much more sensitive to the actual input power being fed to them. Feeding a 12 VDC rated device with 18 volts can cause problems.

Changing to a true 12 VDC -- actually 13.8 VDC -- regulated power supply cured the problems.

I put in a Progressive Dynamics PD4655 power supply. The physical size of the case is the same as the B-W 6345, so it went right in. It also adjusts the output voltage as needed for the battery to keep the coach or house batteries feeling happy, or, it ranges from 14.4 VDC during the bulk charging phase down to 13.2 VDC for the float phase.

My LED lights and all the other electronics (there are a lot of radios in my Elandan) are much happier now.

Enjoy;

Ralph
Latte Land, Washington

Rickf1985 · May 22, 2016, 04:05 PM

You ought to see his "unabreviated replies"! :)rotflmao :)rotflmao :)rotflmao :)rotflmao :)rotflmao

Sorry Ralph, couldn't resist.

HamRad Mobile · May 22, 2016, 04:36 PM

Oh, boy. I walked into that one, didn't I?

Thank you, Rick. And now I know why I was not able to get any response from you via another path.

Perhaps someday I can also offer my dissertation on the virtues and benefits of verbosity.

Enjoy;

Ralph
Latte Land, Washington

ksandbothe · June 05, 2016, 10:27 AM

Thanks, everyone.

It was a short in a wire going from relay switch to the converter.
We tested the solenoid relay switch, it was bad, so we replaced.

We also replaced the converter with a progressive dynamics one, just for good measure, as we have been told the Magnatek 6300 series was "outdated" when it was new. We figured while we were at it, what in the world. The charging system seems to be working better than ever.

Rickf1985 · June 05, 2016, 10:48 AM

We always like to hear the fixes. It makes it all wort the effort. It also helps us in future diagnosis.

Dolores · June 19, 2016, 04:43 AM

Hi, not sure if my problem is the same as this one... Starter and house batteries are always good. House ones are connected to solar panels. Had a puncture Friday and used hazard lights, fridge and little fan above passengers head for 10 mins, plus step in and out quite a bit. Nothing else. Carried on driving for 2hrs with dashboard switch to right side to charge Houses as we were driving. Did not look at battery regulator monitors. By evening and engine 'off' houses monitors were low but starter monitor showed usual lights. Did not use anything else 12v, only toilet, gas fridge and gas cooker. By morning house monitor was still almost flat. RV would not start so used jump start portable pack, one whirl and RV started. Only fridge was working off gas. Drove another 1.5 hrs and stopped. Both monitors were showing the usual excellent lights but had to use portable pack to start 4/5 hours later. Just connect it up, switch on, no need for cranking, and up she fires. RV runs like a bird for as long as engine is switched on. I have switched the 12v isolator on dashboard to 'off' and will be going to RV a bit later this morning. It can't be possible for all 3 batteries to fail at exactly the same time so has anyone got any ides? She is a 1993 Winnebago Brave with the Chevy P30 chassis. HELP!!!! Sorry for length of message too.

Rickf1985 · June 19, 2016, 09:53 AM

Does the voltmeter on the dash show that you have at least 13.5 volts when the engine is running? It sounds like the engine alternator is not working.

Dolores · June 19, 2016, 11:03 AM

Yes. it's got 14.6

Rickf1985 · June 19, 2016, 10:24 PM

The only other thing I can think of with full batteries and a no start is a bad battery cable connection. Take off the terminals, clean them and put them back on. Both ends of both wires.

Dolores · June 20, 2016, 02:24 PM

Sat down. Talked our way through problem. Decided that starter battery was draining the house batteries. Bought a new battery today. Fitted it to RV. Started first go!!!! Switched on house batteries, bottom switch on dash - genny started first go as did lights etc. Who would have thought that such a simple thing would have caused so much problems! Thanks Rick.

Rickf1985 · June 20, 2016, 04:22 PM

I was under the assumption that you had the batteries separated and not linked together. It is not a good idea to leave them tied together except for when driving to charge them or when using the house batteries to jump start the vehicle. One bad battery in a group that are all in parallel will quickly drain the others in the circuit.

Dolores · June 21, 2016, 06:42 AM

I thought you had to keep the rocker dash switch to the right at all times, so that the engine would charge up the house batteries. Now that you have said to keep them separate, we will do so. Will only switch to the right when we are travelling. Don't want it to happen again! Many thanks Rick for your advice

Rickf1985 · June 21, 2016, 10:38 AM

Tex · June 16, 2022, 11:46 AM

Have 1987 Winnebago Super Chief and the same problem others have had, NO DC from house batteries even when fully charged. Have tested transfer switch on dash which meters OK,checked transfer switch in converter OK Obviously the disconnect solenoid must be the problem but before I start ripping and tearing, can someone tell me where the disconnect solenoid is located in this unit.