1997 Ford E450 need switched 12V under hood

[Chandler1]

I'm wiring up my rearview camera and need to tap 12V under hood. Looking for switched 12V or a signal I can wire up a relay fuse board to.

Seems like the driver side fuse box should have a signal to tap but can't figure out how to open backside of that fuse bnox. Anyone have any ideas?

Thanks.

[Murf2u]

If all you need is a light duty switched source you can just hook in tandem with a fuse, or buy a "tapping fuse", it looks like a normal fuse but has a short lead with a female spade connector on it.

The easier way though is to use a thin narrow male spade terminal and slip it into the socket along with one leg of the fuse.

[Chandler1]

Got this solved today. Right in front of the engine fuse box was a 3 fuse add in. Was checking it and it only had one used spot and the fuse removed. Output went to a relay. I connected the fuse up and got a buzzer in my cab and no other indication. Assuming this was an RV add in for a warning of some sort. Maybe slide not home sensor or something simular.

I pulled the output from the relay and plugged my backup camera. Already fused for me.

Still curious what this is but simple to pop the spade off and plug my load to the relay output. In the 5 years I've owned this class C this alarm has never been functional so I think I'm safe.