Flourescent light issue

[zboy59]

I have an issue with the front interior flourescent lighting on an '86 PT40.

There are three switches over the entry door that control the flourescent lights
in the forward area of my bus.(Over the sofa, and side mini-desk salon area).

These lights will not work for long periods of time at all, then suddenly work
fine for a long period, then back again to inoperative.

I'm trying to determine if they all run off a SINGLE ballast. If so, that is
probably my problem, if they're all independantly ballasted ... then I have an
intermittent short of some sort to run down.

The exterior light that runs off the same power loop works fine all the time,
but those are incandescent so ....

I've discovered many time that a simple ground issue kills lights.

Anyone dealt with the ballasts in this part of the bus ? One ? Three ?

Where is it ... and what contemporary model number is it if it's just one ?

I'd like to fix it the first time I have to tear that open ...