With all the switches off on that circuit, put a 12 VDC test light on the line side (battery) of the 12 VDC fuse holder. Then touch the load side (light circuit)where the fuse holder is& see if it lights up. If it does, you have a short to ground, on that circuit, which it should as you keep blowing fuses. Now try this with the w/d turned on to see if vibration turns it off. This way your searching for the short & not wasting fuses. Could also be a bad bulb or socket from the vibration.
Steve & Sharon
'13 Dodge Citadel (hers)
'12 3500 Dodge Mega Cab 6.7 Cummins (his)
'12 Crossroads Rushmore RF38FL (ours!)
Barry, the ADHD x 2 German Shepherd mix, Granddog.