12v light wiring dead

lhowemt · February 7, 2015

Hi Again-

We have one light (of course the main coach one) that is not working. It is the original 2 @12v lamp fixture, on a 1998 Jamboree. It worked when we bought it last fall,, but went out on our first camping trip. I checked the wiring (I am no electrical expert) and I seem to have no voltage and no continuity. I did the same tests on another light that works for comparison. Every other light works. Oh my, how to figure out where the wiring has connectors or a harness, yikes! I guess I am looking for some general advice. Since it is raining out and still winter I am not going to crawl under the beast to see what I can find. I am hoping they don't have connectors in a hidden location and that there will be a way for me to trace back to find where the connection has been lost. I sure am glad I tested this instead of assuming it is the old crappy light fixture!

Laura

lhowemt · February 7, 2015

And all the fuses look fine, but I suppose I should put fresh ones in for good measure. It seems unlikely that with only 8 or so fuses that one would serve that light solely, so I am skeptical the problem is a fuse.

Kirk W · February 8, 2015

I agree with Bill about the bulb. Are we correct in assuming that your readings mean that you are familiar with reading both voltages and resistance? Did you measure from the lead to a known good ground when checking for voltage? The fuses which you say look good must be checked with an ohm meter to be sure as they can fail and not be blown and so look good. I think that it is very unlikely that you have a fuse for just one light.

Is this light controlled by a wall switch, or just by the switch on the light fixture? Switches do fail, light bulbs and sockets fail but the wiring very rarely does so. I am wondering what you used for a ground to measure voltage between when checking for voltage to the light?

lhowemt · February 8, 2015

It is one of those cheapo ceiling mount unit with integral toggle. I unmounted it, and tested the wiring coming out of the ceiling, a probe on each wire with the couch battery switch off during continuity testing. On the working light, I did get a voltage reading and also continuity (with the beep per manual instructions). The bulbs I tested first, swapping out in other fixtures and putting working ones in this malfunctioning fixture. Fixture is similar to this but older:

http://www.campingworld.com/shopping/item/led-euro-lights-double-euro-style-light/74285

Kirk W · February 8, 2015

Did you check that the switch is good, as in 0 ohms when closed and very high reading when open? If it is a double light it probably has a position switch, one on, two on, both off.

You may have a wiring problem but that would be unusual. Being a motorhome there is probably none of the wiring for the lights that is under the rig but it is most likely in the ceiling and in a few cases in the walls. It is most likely that the 12V power goes from the distribution area & fuse panel to the first light, then the next and so on to all ceiling lights in the RV with one fuse supplying them all.

Jimalberta · February 8, 2015

I've seen where the RV manufacturer put a switch in a hard to find place as well as the switch on the light.

lhowemt · February 11, 2015

I've seen where the RV manufacturer put a switch in a hard to find place as well as the switch on the light.

DING DING DING DING DING! We have a winner! Awesome, thank you so much. Your post turned on a very dim memory of the guy pointing out an obscure light switch. I had totally forgotten about it until now. And now the light works. Whew! The downside is two of the plastic covers cracked when I was getting into the non-working and another working one. Sheesh, but I guess 18 year old plastic is going to do that. I think I can find some of those online.... Thanks again!!!! Laura