Getting through the firewall

It would be pretty easy to make the argument that the electrical system in your car is controlling the chaos that could result if you let things go wild. Especially if you’ve ever seen what happens when you accidentally put a wrench across your positive and negative battery terminals.*

One of the big questions that comes up when installing a custom wire system is what to do when passing wires through the vehicle’s firewall. 1968 and up GM vehicles used the connectors pictured below to make that connection clean, reliable and safe.

When applicable, (some systems use smaller original-style disconnects or grommet pass-throughs to prevent major modification to the firewall) our Classic Updates use the same approach, but include a modern fuse panel. This makes what could otherwise be a challenging task simple, and helps keep the chaos out of your new wiring harness.

Harnesses that do not include these connectors

  (when required) would either leave a large, unfilled opening in the firewall, or force the builder to make custom arrangements. It also separates our kits from some of the other modified restoration parts on the market today.

Going completely custom? Our weatherproof 22 port bulkhead disconnect can be adapted to suit any build where a disconnect is desired.

*Please don’t do this to your battery. Bad things happen.