Running a power Cable through the firewall

[thuynsm]

I have a 1995 ford econoline van and am trying to run the power cable for my auxiliary battery from the engine compartment to behind the driver's seat. I am using an AGM batters so it will be inside the vehicle.

I am having a problem finding a place to run the cable through the firewall and would love to hear any ideas. The engine compartment is very crowded and it seems like there are existing "plugs" going through the firewall -- nothing suitable to run a 4 gauge wire through.

Also, is it important that I also run the NEGATIVE battery cable all the way back to the engine battery?

[mjeffrey]

I ran mine through an existing space above the driver's side fender - there's an access hole on the driver's side inside the engine bay. You can reach in from the open driver's door to help thread it through. From there, it exits below the van around the seat area, and I brought it back inside farther back.

I'm out of town so don't have pictures.

You can ground the aux battery to the frame.

Cheers!
Mike.

[Saltydog]

Old post but I just ran into this issue yesterday. I found a rubber grommet in the wall just forward of the drivers door. Perfect access with that gap in the fender. I just ran my wire through the center of it and it comes out where the parking brake is. Its a little tight so I ran a wire fish through first.

[neatvan]

An old post for sure, but figured I'd add what I did too!

I had the same problem. Need to run power from the starting batteries to the house batteries in the cargo area behind the driver seat. I found an existing factory access point under the driver step. You just need to remove the black plastic liner to access the hole. From here I routed the wires into the factory plastic trim that conceals the seat belt. This gave me easy access to the back of the van, and I didn't need to route wires through the cab.

Two pics show the access point from under the van driver step, and the gray plastic trim where the wires come up.

[acerbis]

Hello. Adding to this thread again there is a great access hole near where the antenna passes through. One on the drivers side as well. Its a factory rubber plug that is painted but it's perfect if you drill a hole in that plug, once removed, and your wire now has a grommet.

[posplayr]

I guess there are different ways to do this. One thing that I was using to transition from drivers to passenger side ( on 1997 e350)is the floor support channel just below the front seats. Bear in mind the is an obstruction in the channel so I think you can only get through on the back side of the channel. A snake will fit through but not a large cable. Use the other side.

Running back you can run along the inside of the outer walls , parallel to the rear heater and ac lines. In frount you can snake up into the inner fender to get to the passenger side start battery.

Rather that run cables though the floor or firewall I have used bulkhead battery connections for a cleaner install.

https://www.amazon.com/gp/aw/d/B09TL...haWwp13NParams

https://www.amazon.com/gp/aw/d/B08Z1...haWwp13NParams

With these bulk head connections you never run the cable through a wall. I have passed them through the gas filler tunnel ( the protrusion into the interior for the gas filler tube) or you could probably use the Floor as well.

[JWA]

Originally Posted by posplayr

Rather that run cables though the floor or firewall I have used bulkhead battery connections for a cleaner install.

https://www.amazon.com/gp/aw/d/B09TL...haWwp13NParams

https://www.amazon.com/gp/aw/d/B08Z1...haWwp13NParams

I've used similar from Blue Seas Systems to great effect. With the correct shrink tubing and terminal end insulating covers you're creating a much more sound electrical path, one that's a bit easier than looking for thru-passages inside the body.

Here's the type I've used running a 4ga cable from the engine bay through the firewall and eventually into the rear cargo bay: https://www.bluesea.com/products/cat...ugh_Connectors

Plenty of options as POSPlayer and I are showing----better installations IMHO.