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Topic: 12V -side question (Read 2879 times) previous topic - next topic

Re: 12V -side question

Reply #40 –
Quote from: LTG –
David, I know you have checked and the salesman switch in on. But have you checked to see if the salesman switch is working?

Larry
I just looked at the schematic again for the umpteenth time. The salesman switch is the biggest suspect. It appears by the schematic that it would give the symptoms that David has if it was turned off OR not making contact.

Roland

Re: 12V -side question

Reply #41 –
I don't think it could be the salesman switch.  When I'm hooked to shore power and turn that switch off, all my 12v lights go out.  All David's 12v systems work when he is plugged in.  Also, I'm able to start the generator with my salesman switch off.

I could very well be missing something, but that just doesn't seem like it could be the problem.

Re: 12V -side question

Reply #42 –
Douglas, David said that he has an inverter and a converter/charger. I believe from his statement that his inverter and converter/charger are two separate units. I believe that your coach has an inverter/charger and no converter/charger. These two system function differently. I am not sure about David's Foretravel but on some motorhomes with a converter/charger, with using shore power, the converter powers the 12 volt system directly and at the same time provides a charge to the batteries.  In those systems, when on shore power the converter will provide power to the 12 volt system even with the salesman switch is turned off. And, on some converter/chargers, they will function when on shore power even with the battery or batteries removed. Having said that, I am not sure how the converter/charger works on David's Foretravel.

Larry

Re: 12V -side question

Reply #43 –
Normal lead acid battery voltage is 12.6 , would suggest using a Volt meter and start snooping.

Re: 12V -side question

Reply #44 –
Quote from: LTG –
Douglas, David said that he has an inverter and a converter/charger. I believe from his statement that his inverter and converter/charger are two separate units. I believe that your coach has an inverter/charger and no converter/charger. These two system function differently. I am not sure about David's Foretravel but on some motorhomes with a converter/charger, with using shore power, the converter powers the 12 volt system directly and at the same time provides a charge to the batteries.  In those systems, when on shore power the converter will provide power to the 12 volt system even with the salesman switch is turned off. And, on some converter/chargers, they will function when on shore power even with the battery or batteries removed. Having said that, I am not sure how the converter/charger works on David's Foretravel.

Larry

That's all news to me. ;D  Yes, David definitely has a separate inverter and from his (converter/)chargers.  Actually he has two chargers.  Well, now I'm going to have to re-think this whole thing with that extra info.

Re: 12V -side question

Reply #45 –
Quote from: LTG –
Douglas, David said that he has an inverter and a converter/charger. I believe from his statement that his inverter and converter/charger are two separate units. I believe that your coach has an inverter/charger and no converter/charger. These two system function differently. I am not sure about David's Foretravel but on some motorhomes with a converter/charger, with using shore power, the converter powers the 12 volt system directly and at the same time provides a charge to the batteries.  In those systems, when on shore power the converter will provide power to the 12 volt system even with the salesman switch is turned off. And, on some converter/chargers, they will function when on shore power even with the battery or batteries removed. Having said that, I am not sure how the converter/charger works on David's Foretravel.

Larry
That is what the OEM schematics show an inverter and a separate converter.

Roland

Re: 12V -side question

Reply #46 –
Keep in mind that the salesman switch only powers off the circuits that are not directly wired to the battery.

Very old style converter/chargers has two circuits, one to power circuits that could operate with dirty dc, notable incandescent lights, and one to charge the battery, which in turn provides clean dc power to tvs, radios, and other noise sensitive electronics.

Newer style converter/chargers were really chargers only. Smart chargers too. All dc power came  from the battery, with no separate converter sourcing dirty power.

Re: 12V -side question

Reply #47 –
Latest update: I shut off all power to the coach, disconnected all four battery terminals on the house batteries, then turned the power back on. The battery cables showed 14.46 volts, which tells me that the charger/converter is working properly and the house batteries are being charged.

I turned the power back off and headed to the other side of the coach where I put a towel over the copper gas lines under the salesman's switch. Either the factory or a PO decided that four screws weren't sufficient to hold up a small plastic cover, so some sort of sealer was added. Once I got that cut I found that the whole underside of the switch is covered in black electrician's tape.

I put the cover back on, without adding more sealer, and went back to the other side of the coach. The batteries had been disconnected for 20-30 minutes, so I checked their voltage. 12.86 on one and 12.87 on the other.

I put everything back together and checked for any inside 12V activity. Nothing.

Re: 12V -side question

Reply #48 –
All the electrical tape around the switch seems suspicious to me, but maybe I am a suspicious type of person when it comes to PO's. I would have removed the tape and made sure the switch is functioning properly. Process of elimination.

Roland

Re: 12V -side question

Reply #49 –
My son is here, and he came up with another test. I put the meter on the battery while someone tried to start the generator. We wondered what happened to the battery voltage. The drop was only 0.04V.

Re: 12V -side question

Reply #50 –
Is this the schematic for your system?
Irwin

Re: 12V -side question

Reply #51 –
Kind of looks like it. The diagram looks like there are three large breakers, and I think I have only two. Maybe the third one doesn't look like the other two, though. This will bear more checking. I'm going to be home Tuesday, waiting for propane, so I can poke around a bit more then.

Re: 12V -side question

Reply #52 –
Quote
Either the factory or a PO decided that four screws weren't sufficient to hold up a small plastic cover, so some sort of sealer was added. Once I got that cut I found that the whole underside of the switch is covered in black electrician's tape.
I'm betting that's factory. Here's a photo of mine. Same deal.
jor

Re: 12V -side question

Reply #53 –
Jor, that looks EXACTLY like what I found. I'll probably clean the tape off tomorrow.

Re: 12V -side question

Reply #54 –
Quote from: kb0zke –
.....................I turned the power back off and headed to the other side of the coach where I put a towel over the copper gas lines under the salesman's switch. Either the factory or a PO decided that four screws weren't sufficient to hold up a small plastic cover, so some sort of sealer was added. Once I got that cut I found that the whole underside of the switch is covered in black electrician's tape. I put the cover back on, without adding more sealer...........................
Guys,
 ??? ??? ??? ??? ??? ??? ?
If you mount a switch in a potentially explosive (Propane) environment, you either need to use an industrial, sealed, explosive environment switch (= expensive) or you can use a switch that you already have and carefully seal it off from the environment (what Foretravel did in this case).  And, the tape on the terminals is there to prevent your dropped (or in motion) wrench from bridging (+) 12Vdc from the bare switch terminals to the gas piping or other ground point, creating sparks and the potential for an explosion.
Just remember that 6% or less of all RV fires originate from defects in refrigerators and 94%, or more, are caused from other sources (many of which are poorly implemented or thought out "upgrades" from the RV's original design).
Neal

Re: 12V -side question

Reply #55 –
Can't drop a wrench on those terminals as they are on the "ceiling" of the Compartment. In addition they are covered and the cover has some type of caulking sealing the terminals. Maybe a bit of overkill. I would have used an insulating spray. Would still remove the tape to assure that everything was hunky dory as far as the switch was concerned. Then resell and cover.

Roland

Re: 12V -side question

Reply #56 –
I for one am eager to hear what the issue is with this coach, not as eager a Dave but eager nevertheless.

Roland

Re: 12V -side question

Reply #57 –
Just heard the weather forecast and it sounds like I can work on this today. I'm going to warm the coach up to about 80, then kill all the power and trace wires. That will include taking that tape off. After I'm done with the switch I'll retape it. After I know where wires go I'll reconnect the house batteries and see where the electricity disappears.

Since all is good when we're plugged in, the only inconvenience is when we're traveling. Yesterday we cranked the heat up to 80 while we were packing up. Once I unplugged, of course, the furnaces stopped working, but the engine heater kept us nice and toasty.

I'll report what I find tonight.

Re: 12V -side question

Reply #58 –
Dave, any progress on your 12 volt issue? Inquiring minds want to know.

Roland

Re: 12V -side question

Reply #59 –
Well, no. The weather hasn't been very cooperative, and we were supposed to head down to Stillwater Wednesday. Unfortunately (or fortunately) the air compressor decided to quit on us, so we're stuck here at home until a new compressor and air dryer can be installed, which won't be until Tuesday. Tomorrow looks better than today, and Monday looks better yet, so we decided to spend today cleaning inside the coach.

I have been thinking about the problem, though. One test I want to run is to have some 12V stuff on, then have Jo Ann turn off the 120V while I measure the voltage at the batteries. Then I'll disconnect the batteries and have her turn the 120V back on. I talked to my b-i-l who is an electronics tech who worked with battery stuff for many years. He is also somewhat suspicious of the batteries, even though they were new last spring. I'd like to leave them completely disconnected for a couple of hours and see what they show.

He wondered if the charger/converter had two outputs - a charge circuit and a converter circuit. The answer is no. Each box has one + and one - lead coming out. The two outputs are in parallel (just like the old MagneTek one were). I haven't followed the wires completely, but it looks like those leads go straight to the batteries and then off to the rest of the coach.

One interesting thing we've found is what runs on the house side that I thought was on the automotive side. The power seats and dash radio are on the house side. No listening to the radio while driving until this is fixed. I had moved the navigator's seat forward while rotating it, and forgot to put it back. Jo Ann complained about the lack of leg room, and that's when I found that my seat wouldn't move, either.