Blown Fuse

[Mich48041]

If your troubleshooting isolates the problem to fuselage wiring, one of the first places I would suggest
looking is where the wiring is captured by a metal plate above the rudder pedals.

Since the plane was one of the first ones built, it might not have the "Over Rudder Wireway", Van's part number F-12125
Another suspect area is where the wires pass through the bottom of the instrument panel.

[thomasyost]

You might want to verify that you are using the correct size fuse.

I only say this because I was watching the RV12 Pilot YouTube videos recently and he had a similar issue where the original fuse size was incorrect and had to be replaced. He mentioned in a subsequent video how there was an instruction to replace the 5a fuse with a 7.5a fuse that was missed.

[RV12Pilot]

Thanks for all of the suggestions

[hevansrv7a]

Originally Posted by Mike S

...snip..

If that doesn't work, look for high resistance like corrosion in the bulb socket, loose screws or push on tabs. Even loose fuse to holder contact.

I am no expert but doesn't a blown fuse say there was too much current at that moment? How would high resistance cause MORE current to flow?

[NinerBikes]

Originally Posted by hevansrv7a

I am no expert but doesn't a blown fuse say there was too much current at that moment? How would high resistance cause MORE current to flow?

High resistance can mean voltage drop, which would/ could increase current flow, to get the same amount of watts required.

[rapid_ascent]

So the fuse is blowing for excessive current. What that means is somewhere you are probably getting a short to ground as others have mentioned. A couple of common faults are open circuits where one of your lights may not work and a short circuit which would cause the fuse to blow. For that to happen then the wire for your lights has to be touching a ground of some type or the grounded airframe.

This probably means there is some poor workmanship on that circuit. A connector that is not properly insulated or crimped, or a wire who's insulation has been cut and contacting the airframe. You will need to start tracing the wiring. Sometimes wiggling the associated wires may show a problem.