Monday, January 24, 2022


RV fluorescent lights gone dim – What gives?

By Russ and Tiña De Maris

An RVer who was hooked up to shore power reported a sudden “dimness” in his fluorescent lights. Then a short time later, they simply failed to turn on. Meantime, his incandescent lamps were shining away brilliantly. At first, he wondered if it might be a ballast or tube issue, but since the problem was afflicting ALL his fluorescent fixtures, he knew something more had to be going on.

Well, RV Tech Detectives, what do you think?

A little probing with a voltmeter on this issue soon pointed out the source of the mystery. Since fluorescents can be adversely affected by a.c. “ripple current,” you may find your “flowers” to be wired directly to the house battery. In this case, the house battery bank was “on it’s way out,” and registered less than 9 volts — far below the needed startup voltage for a fluorescent fixture. The incandescent lighting circuit, however, was drawing plenty of power from the RV power converter and still giving effective light. But switching off the power converter left everything in a grave dimness.

Prescription? Replace that house battery bank!

##RVT788 ##RVDT1312


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Glenn B Wray
1 year ago

Had a problem with a bathroom light. When turned on the radio in the front on the dash came on. Took it back where it was purchased. The tech said he had seen it before and had a good idea what it was. He replaced the floresent light fixture near the switch. Yes it fixed it, don’t know how or why but it did.

Terry Hennessy
1 year ago

CONVERT ALL incandescent and fluorescent TO LED AND EXTEND BATTERY LIFE X8-X10. When I first bought rig w/ incandescent, the FAN ran if ONE light on over 30-seconds; since conversion, have NEVER heard it run (3yrs now)

1 year ago

I haven’t seen it all but if the rig’s florescent fixtures were wired directly to the battery while the others were being controlled by the converter output -it would be a strange thing. While on shore power, the converter should be powering everything that’s 12v. Good thing though that they replaced (or will be replacing) the battery bank.

1 year ago

Good tip. Another good idea is to upgrade to AGM Batteries, and solar!

Ralph Burns
1 year ago
Reply to  Ran

If money is no object.