I have a 1998 F-150 XLT Supercab and I can't find a single place to run my 12V power wire through the firewall. I've tested all of the grommets and they all run into a wall or end up by a moving part in the engine. Can someone tell me where to find a video showing the best way to do it with the right truck? Cause every video I find it's either a different year or an Expedition and their grommets work for them. Or if you could send me a video of it or send me a step-by-step process with pictures please.

 

Like you I couldn't find a spot to run it through in my old truck, so I bought a firewall grommet for the size of the power wire I was using and drilled through the wire wall, it comes through right behind the floor mat on the passenger side almost high enough where it's tucked under the dash, but still easily accessible to feed the wire through. I can get a few pictures of it if you'd want.

Another place I've seen people still through is the flat part under the back seat rest where the carpet ends.