View Full Version : DC electrical switch?

12-26-2017, 06:19 AM
I have a 2006 King of the Road Royal Villa. There is, what I thought a main shut off switch to the trailer I thought for DC voltage. It's a large black knob on a red or orange backing.

Please see picture. I did put a new intelligent converter to replace the old one. Replaced wire to wire which was simple enough! Seems to be working fine charging the batteries!

I accidently left the overhead LED lights on, but always shut off the large switch in the control panel with all the small DC fuses. Next day I opened the trailer up to work on it and forgot to turn the main switch on and noticed the lights were on. I thought I must have forgotten to turn the switch off. I opened the panel and to my surprise it was off, but the lights inside were on?? Sure is odd! I need to do some checking with my Volt meter.

12-26-2017, 08:29 AM
Well, lights are getting power from somewhere--faulty cutoff switch?

12-26-2017, 09:21 AM
Makes me wonder? Time to break out the volt meter. I’d swear it worked before. I did add the new converter, but it was a wire for wire swap except the direct case ground to the body/frame of the trailer.

12-26-2017, 04:20 PM
Looks to me like only 1 circuit is connected to switch thru a relay?


12-26-2017, 05:53 PM
I don't think so. If your looking at the block it's tied to, there is a jumper. Look close. I need to get the volt meter out and do some checking.


12-27-2017, 12:31 AM
Any chance the switch is defective and that it still has closed contacts when it's in the OFF position? Also, is it possible a single or more than one strand of wire crossed over from one terminal to the other when the wires were attached to the switch and weren't seen?

Every time I start troubleshooting I ALWAYS remind myself to use the KISS principle and start checking the simple and sometimes overlooked possibilities first. As example, it's kind of like troubleshooting a computer that has a network connectivity problem, One could start thinking the problem could be a bad network card (NIC) or maybe the NIC drivers need updated or something worse when the actual problem is the network cable isn't plugged into the NIC port. Not saying simple causes like these are necessarily the case with your switch, but could be. Hope you find it easily.

12-27-2017, 05:51 AM
I fully agree, that many times the simplest thing is the answer. I'll unhook wires and do a continuity test on the switch first. Then if it's OK, we run wires!

02-28-2018, 01:04 AM
Did you ever discover the issue with the lights staying on with switch off? Those Perko switches are made to pretty good standards, mostly marine use.

02-28-2018, 05:39 AM
While hooked up to shore power, the converter supplies the 12 volt DC directly bypassing the switch. If you disconnect from shore power the switch works fine. I installed a new switch thinking problems solved....WRONG. When I ran a continuity check on the switch I removed, it was fine and I had the same problem with the new switch!

Once you unplug from shore, the switch works fine or unplug the converter. You have to keep that in mind when working on anything that is 12 volt if you need the power off.