Headlights and running/parking lights not working

[pastordon]

Hello everyone my headlight and running light issue has really got me stumped and I’m looking for your help

Has anyone ever had issues with headlights and parking/running not working?

I have a 2000 Winnebago adventure 35ru on a Ford F550 chassis. My headlights and running lights will not come on with the engine off. When the engine is on the driving lights will come on and when I pull the signal indicator into the pass position the high beam lights will also come on so, I know the lights do not need to be replaced. However at no time do I have running lights. I can turn my dimmer switch all the way on and my overhead courtesy lights will come on.

Here is what know and what I’ve done so far -

All turn signals work and all brake lights work

I have no power to fuse number 41 and 35. And I have checked all fuses with a volt meter. How would I test the headlight switch and what is the power source to fuse 41 and 35.