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AKwanderer · 07-31-2011, 12:50 PM

Alright, so I've got myself a lovely 87 Travel Master Savannah motorhome. I've had this for a few years now and it's had some minor electrical issues in the back. It's had a drain somewhere and it would have problems charging at times but I could never figure out what it was. So recently I lost all power to the back and with my handy dandy little tester I was able to track it to this device (First picture). It has power going in from the vehicle battery on the left side, but it doesn't have power coming back out of it. On the right side that wire goes back to the camper somewhere, I assume to charge the battery or something along those lines. Now when I jump the two poles it runs power to the back just fine. I also noticed a light buzzing noise occasionally coming from it. So I need to know what this thing is called, what it does, and where I can get a new one?

Also, I was going through the rest of my electrical system while my 110 was plugged in and I noticed something from my electrical box making a noise. Now from what I was able to find out was it's common for older rigs to make a little noise but this is quite loud. It's the click with a metallic pop sound. But one thing I did notice is between the click and the pop there is a buzzing sound and everything in the back goes dim like there is a major power draw. I've noticed the noise coming from this thing here (second pic). Is there anything I can do to quiet this? It makes it hard to go to sleep in there.

BA-in-Mich · 07-31-2011, 02:11 PM

Top picture, is there 12 volts going to the small wire? Second picture, That is a transformer What it goes to is most likely the 120 volt a/c to 12 volt d/c converter. If all it is doing is humming a little all is probably normal if it is rattling the most likely cause is loose lamination's. That is not a big deal either just annoying.
Have you tried putting 12 volts to the side terminal on the top picture?

want2camp · 07-31-2011, 05:27 PM

The top picture is a solenoid. They are used when you want to be able to "switch" large amperage draw items. Power comes in on one side and goes out the other when activated. The small terminal on the front activates it when it gets power from your switch.

pwf16129 · 07-31-2011, 06:39 PM

they are right the one on the left is a solenoid but be aware there two types of solenoids starting and constant duty, you want the constant duty it is roughly $30.00 while the starting duty is $12 or so.
the starting duty will literally melt if used in place on the constant duty, the constant duty has finer windings and can take being power on continuously.
the other is self explanatory. someone made this mistake on mine before i bought it it ran down the inner fender it got so hot.
and the second is a transformer mark the wires , tape the wires and find and disable the fuse/breaker that powers it take out go to a radio shack an see if they can match it if not an rv parts sales.
dimming lights isn't a good sign it could overheat and cause problems.

good luck and happy travels

ahicks · 07-31-2011, 07:41 PM

The click with a pop sound could be coming from a circuit breaker that's tripping, cooling off and resetting, the tripping again. The lights are dimming because of a large drain on the converter while the breaker is set. You need to shut this thing down until you figure out what's causing this problem - prior to it causing more damage! Power from the converter should lead to a fuse panel. You could start pulling fuses until that breaker stops tripping (popping), but my bet is something bigger is causing the problem. Maybe in a line to your AUX battery?

The solenoid in the top picture may or may not have an issue. You need to figure out where those other 2 wires are going to know what it's supposed to be doing to do any good diagnosing it. Does it click or have power to the smaller terminal when you turn the ignition key on?

Airtool · 07-31-2011, 08:13 PM

AK ! The first picture is a solenoid, looks like it would be used to power a 20 to 30 amp.circuit,like headlights,cooling fan or something drawing that kind of power.
The second picture is a transformer,used to step up or down ac voltages.
can not tell from the picture what it would be a part of. Could be in a battery charger circuit. need more info. or a wider picture of the area its sitting in.

Dick.

AKwanderer · 08-01-2011, 12:07 AM

Ok, sorry it took a little while to get back to you fine folks but here are my findings. There was no power going to the middle post, ~12.6v going into the left, ~3.3v coming out the left, and the metal housing on the solenoid was reading ~3.6v. It definitely has to do with the rear power, possibly charging or something along those lines.
Now me being one for simplicity I was wondering if I would be able to cancel that solenoid and run a switch to the inside of the cab? That would be handy as I could park somewhere for the night, flip the switch, and have my vehicle battery be separated from the house electrical system so I never run that dead.

want2camp · 08-01-2011, 05:01 PM

While it is possible the solenoid could be bad I don't recommend bypassing it. Trying to connect those large wires to a switch is a pain plus I would be very very worried about the switch overheating and causing a fire which is why the solenoid is there. You really need to trace all 3 wires and find out where they go, especially the small brown one. That is the trigger wire and in order to properly diagnose the solenoid you need to know what is activating it, i.e. the ignition key or toggle switch, etc.

Nuge · 08-01-2011, 05:25 PM

My old RV has manual battery switches mounted under the hood. That might be an option if you want simple. You might just have lost the "on" signal to that center stud on your solenoid.

My converter/charger hums pretty good, too, but without a schematic and bigger pictures we can only guess if you actually have a problem or not there.

AKwanderer · 08-01-2011, 11:06 PM

Well the wires to the solenoid really aren't that big. The red ones are probably 14 gauge and the brown one is about an 18 gauge. The brown wire runs down into some connector that had 5 other wires coming out of it so I'm not too sure about that. I've run my own electrical systems for lights and such on other vehicles so I know I'm not running that much power in there. The convenience of it being right on the dash rather than a toggle under the hood is pretty tempting. I'll try to find any schematics of that area and I'll get some better pictures tomorrow.

ahicks · 08-03-2011, 05:24 AM

Just a thought, but wondering why one might go to the trouble of installing a switch on the dash - that he's not going to know when to turn it on, or what to expect when he does?

If you check the solenoid out to the point where you understand EXACTLY what it does/suposed to do, then maybe you could make a case for your idea?

Why don't you try jumping the solenoid to see what happens? Take the 2 larger wires and touch them together? At this point, for all we know your horn or your headlights could come on. You could be fixated on something that has nothing to do with your problems.

AKwanderer · 08-03-2011, 02:17 PM

Well as I stated in the first post I've already jumped the poles. Without it jumped I have nothing in the back as the house has run dead. With the poles jumped I have full power to the back and the battery starts charging. So I know they don't go the horn or some crazy thing. I just wasn't sure what the device was called or what it did, I just knew where the electricity went.

ahicks · 08-03-2011, 02:37 PM

Quote:

Originally Posted by AKwanderer

Well as I stated in the first post I've already jumped the poles. Without it jumped I have nothing in the back as the house has run dead. With the poles jumped I have full power to the back and the battery starts charging. So I know they don't go the horn or some crazy thing. I just wasn't sure what the device was called or what it did, I just knew where the electricity went.

On the bold, sorry, I must have missed where you said that. The solenoid, when wired into the circuit as you describe is called an isolater relay.

That small terminal should be hot when the ign. key is turned on. If you can arrange that, and the solenoid is functional, you'd be good to go with a charge line to the aux batteries - done automatically. The switch plan would work, but it's going to be something else you'll need to remember every time you get behind the wheel. Forget it one time as you leave the driver's seat and all of your batteries will be on line at your destination - with the potential for all of them going dead very real - leaving your coach dead in the water without any options.

want2camp · 08-03-2011, 04:50 PM

If your getting power on the solenoid housing then there is probably an internal short. I realize the wires aren't all that big but since it seems to control charging power to the back and power to the back my concern was the amperage that might overheat a toggle switch. If you touch the positive meter lead to the small terminal and the black lead to a ground with the motor running do you get 12 volts? If not then there possibly is a problem with that bundle of wires you mentioned. Why not just replace the solenoid then use a toggle switch on the dash to activate it?