My dodge ram blows 18 fuse when I turn on the parking lights dash lights don't work along with the dome and cargo

Could be a wire or bulb shorted out some where. Has it been in any fender benders or off roading situations that might have pinched or snatched the harnesses?

No just started it one morning and it went out

All lights headlights parking lights all work

Will the dome light work and not blow fuse if you don't turn on head lights?

If I don't turn on the parking light

Yes

Replaced the switch

Also replaced headlight, just throw money at it now not good

Don't want to do that. Let me do some digging. Will get back to you soon

This k I should try replacing the relay

How can I test the relay can I use a ohms meter

Found the problem the radio dash illumination wire was grounding to the frame

Causing the dash lights and dome, cargo lights to short out, after market radio was put in truck 8 years ago, years of change in temperature caused insulation on wire to ground out Thanks for all who responded very helpful thumbs up to Cargurus T

Sure glad you found it. And thanks for posting what you found. This info may be helpful to other owners in the future. Drive safe.