Some lights work -some don't

[empty46]

First off thank U for the welcome. I'm a first time Rv'er. I purchase a 1978, 29" Pace Arrow that needed work. I have in working order except the upper marking lights. The center one in the back and front work, but not the others. I have no manuals and have chedcked the fuses (that I can find) bulbs and wiring I can see. Has anyone any ideas or suggestions. I would be very thanful.

[Gary RVRoamer]

It is common for marker lights to suffer from moisture and corrosion. Pull the covers off and try to clean the bulb sockets and wire connections and maybe replace the bulbs. And you can check for 12v at each light housing. You may need to replace the lights themselves.

[Midnite-CTD]

Also be sure to check the grounding on each light, since i'm pretty sure each bulb will be grounded individually?