Total Light problem with fog light switch glowing

[Superone1973]

Hello everyone. I have bought myself a lefftie motorhome ford riviera 1996. On the way from buying the rad has got a leak, easy fix. My real problem is when it came to night time. I turned the lights on and it causes problems. My indicators start not working like when a bulb is blown, flashing fast. The fog light switch glows , brighter if you press it. All the lights at the back seem to light up. . I think maybe its a bad fog switch as it seems to have this problem when the fog light switch comes on which is not all the time. Any ideas,? Or no night driving lol Thanks for any help.
One other thing in he dashboard the fog light symbol comes on when you turn on below fuel gauge. Surely I should have a symbol so I know lights are on

[gotgcoalman]

I'll start the ball rolling with a bad earth.
Check back light clusters

[Superone1973]

I'll start the ball rolling with a bad earth.
Check back light clusters

With the bulb earth's. Or is there a separate earth. First I need to find my keys and we are in a big field with long grass and a two year old:-(

[Superone1973]

Found my keys after. Someone handed them into the camp office, just after going through the recycle bin lol

[gotgcoalman]

Not sure on vans but chasis cab has an earth on the rear X member that's prone to corrosion