Bathroom Light Not Working

I went to turn on the overhead flourescent bathroom light today, and it flashed briefly and went out. I checked fuses, circuit breakers, and the GFI, and they're all OK. I removed the bulbs to test for power at the bulb receptical electrical prong contacts and I'm not getting any voltage there. All other electrical outlets and accessories are working fine. I haven't tried replacing the bulbs yet, but shouldn't I be getting power at the contacts without the bulbs in place? Any ideas?

[dcrdark]

It's probably the ballast is shot. We had the same problem last year. You can call the factory and order a new lamp. I just replaced it with a new lamp from Camping World.

[Bill]

TW -

Fluorescents are funny. I'm not sure what voltage you would expect to measure at the bulb contacts, but measuring it is not straightforward. My TM is in temp storage on the other side of town, or I would check for you.

I think that when you first turn the switch on, you should get 12 VDC from one of the four pins to ground - but not from the other three. This would be the preheat voltage, assuming these are preheat lamps (which I'm not sure of).

After a moment or so, you should get a high voltage (300 VDC?) from one of the pins at one end to one of the pins at the other end - but there is no way to tell which one, at either end. So you have several combinations to try. This would be the operating voltage. And if there is no lamp present, the ballast (which makes the high voltage) might not come on.

So you see why measuring the voltage is not as simple as it is with an incandescent fixture.

You might start by buying a replacement tube from WalMart - they are only a couple bucks.

Assuming the thing was made by ThinLite (which is my memory), you can buy replacement ballasts from
http://www.wind-sun.com/Misc_AE/Thin_Lite.htm.

In the end, though, it may be easier to simply follow dcrdark's recommendation, and buy a new fixture. Camping World, or Wind-Sun at the link above, can help you out.

Bill

At first I thought it was dropping out when the battery was discharged (which I have seen before), but we have seen it drop out on a freshly charged battery. Does seem to last longer on AC, and we did go a weekend on AC with no 'outages'. Came back on battery on our recent trip.

I have replaced the bulbs. BTW, I read elsewhere that TM charges $50 for a replacement fixture. I spent $12 at Wal-Mart just for the bulbs.

I'll be digging out my voltmeter, just to confirm I have good +12 VDC after the switch. If so, I'll probably replace the fixture.

I've got 12V at the circuit board inside. Probably will be more efficient to replace the fixture. Looks like ~$40 at Camping World or the original manufacturer.

I may try JC Whitney: http://www.jcwhitney.com/webapp/wcs/...atalogId=10107

Here's a source that has it for $35 (thanks windbreaker!):
https://www.rvsurplussalvage.com/cat...roduct_id=1317

[Bill]

Another source for DC fluorescents (and repair parts) is Northern Arizona Wind and Sun
http://store.solar-electric.com/thinlites.html Click on DC Lights or Thin Lights.
I've dealt with these people face-to-face, and bought quite a bit from them. Good folks, I guarantee.

Bill

I finally broke down and ordered a Thinlite from Camping World:

6917 30W Fluorescent Light $39.99
Shipping $7.00
Sales Tax $3.76
Total $50.75

Decided I was wasting too much time troubleshooting and needed to move on :-)

The light is far brighter than the old and my wife loves it.

Had to drill 3 new holes in the ceiling to mount it.

Discovered that the splices to the wiring were WRONG size. They were using splices rated for 18-14 AWG with 12 AWG wire, which will cut some strands in the 12 AWG that the lamp taps into.

This was not part of my problem, but I decided to 'fix' that mess by using wire nuts. Hope they don't vibrate loose.