Everything works until I....

It was simple... After a brief lesson with a multi-meter and checking around the fuse block area as DrewE suggested, I found it. One of the 40Amp re-settable fuses had tripped. Flipped it and now its good. I just need to find out what tripped it.

Do not discount any of the answers given here, One may work very well for you, however, either before or after you trouble shoot your problem, got to this link and read up on what the system components do. Without fail read the 12 volt side of RV Life.

There are three items that will help you testing for electrical power, a DMM (Digital MultiMeter), 120 VAC and 12 VDC test lights, and a Non-contact voltage detector. As mentioned 3 hands for one, 2 or 1 hand for the two and one for the non-contact detector. The DMM is for MULTI functions 12 and 120 volt reading is one and the test lights are single function, the test lights are usually single voltage testers and the detector is 120 volt only.

I will say that in all the manuals and RVs I looked at I've never seen the Battery Disconnect switch labeled Salesman Switch. Than is really out dated now you'll seldom if ever hear it called that.

Saw this same problem (which by the way is common) on anoter forum

Suggested the following
Battery Disconnect (Salesman switch)
Disconnect solenoid (the device that actually does the switching)
BAD CONNECTIONS (The winner in that case)
Bad cable (had that found it before it was a proglem, repalced it)
Blown main fuse or circuit breaker (Battery)

But first, Make sure the batteries are fully charged.

Rather than a volt meter,, which means you have 3 things to hold and look at, I like a test light, This is a device that looks like an old fashion ice pick (and in fact may be used as such) but witha clear or translucent handle and a wire coming out the handle.

The wire has a clip (Alligator clip usually) on one end and there is a light bulb inside the handle

You start by touching the clip to one battery post and the tip of the pick to the other BRIGHT LIGHT = Good.

now with the RV not plugged in move the clip to a non-painted frame part LIGHT GOOD Dark bad ground cable

Move out along the positive wire, When you come to a device check both BIG posts (if it has both big and small) .. When you need to move the clip, touch the last tested good point to insure you still have a good ground.

Continue till you find DARK, problem exists between LIGHT and Dark.

fuse on the control circuit. Look at the battery disconnects. Some have the fuses mounted directly to them.
Use meter or test light as it could also be a bad ground in the same area.
The control circuit should be attached to the battery side of the battery disconnect large post.

Convertor not INVERTER right MIKE???? You really need to GOOGLE "12volt side of life" READ and LEARN

What I do is measure across the battery terminals with a VOLTMETER. If the battery is full charged it should read around 12.6-7VDC.

Then go connect to Shore Power and your VOLTMETER should now read 13.6VDC or whatever mode the smart charger is in. This tells you the battery is connected and all the fuses between the battery and the 12VDC Distribution Panel is good. Of course everything should be working now too... Most everything runs off the 120VAC circuit breakers and 12VDC ATC Fuses located in the Power Distribution Panel.

Another good test is just turn on the ceilings lights. They run off of 12VDC and if they are burning without shore power connected then your battery is feeding the 12VDC Distribution Center ok. When you turn on shore power with the ceiling lights on they should get alittle brighter perhaps...

I'd turn off shore power and start tracing from the battery terminals and see where you lose the 12.6-7VDC reading.

Most often it is BATTERY DISCONNECT Switch opened somewhere... Could even be a bad terminal connection that needs cleaned up..

Here is a typical 30-AMP Power Configuration Diagram of all the things that needs power just to give you an idea what feeds what.....



Roy Ken

Toddupton wrote:
It sounds like you are flipping the sails an switch and not the battery disconnect switch. If you are plugged in the battery disconnect should not turn off lights. I bet you have another one someplace else.

I have a '98 Coachman Santara class C, and the salesman/battery disconnect switch will turn off the house 12V power even when plugged in. The converter is wired on the battery side of the switching solenoid, not on the electrical panel side. There is no other disconnect switch (at least on mine).

It sounds as though there's some fault in the 12V wiring around the battery. At least on mine, the house battery connects to a master fuse (175A I think), and then to the isolator relay, to the generator (a heavy cable), and with a very short heavy cable to a little bus bar with space for four cube/self-resetting circuit breakers. I've revised the wiring there a little bit on mine, but originally one of the four slots was empty, one had a 20A manual reset breaker that supplied power to the entry step, one had a 6A breaker that supplied power to...something, I think the dash radio preset memory, and one had a 40A breaker that connected to the house 12V fuse panel and to the converter output (two wires on the same stud).

If you have the same circuit topology, then the fault would seem to be either the 40A breaker and/or its connections, or the connections to the little bus bar, assuming only a single fault. If the isolation relay is not working or the charge line from the chassis to the relay isn't working (there is a fuse for it under the hood), then it could also be that and the main fuse...but if the generator shows any signs of life, the fuse is OK. My money would be on the 40A self-resetting circuit breaker needing replacement.

Most rigs have an auto circuit breaker (http://www.delcity.net/store/12V-Auto-Reset-Circuit-Breakers/p_198669) near the battery bank. When they go bad the battery is essentially disconnected from the rig - so charged or no you don't get DC power when your not plugged into shore power. Worth a look.

It sounds like you are flipping the salesmans switch and not the battery disconnect switch. If you are plugged in the battery disconnect should not turn off lights. I bet you have another one someplace else.