My Switched Auxiliary Power Circuits

[Paul Hauser]

Several users have added auxiliary power circuits that are switched on with the key instead of on all the time. I was inspired particularly by DonShockley and MMontMiny, This is how I did it.

This assembly was made first. The relay will power the line side of three fuses, the load side of each will be routed to the Upper console, Lower console and Rear of the van.

The relay is triggered by the PAM circuit (R37 under the hood), an option not installed in my van, but it becomes hot in the Run (II) and Start (III) positions.

Both the Power to the relay and the switch leg have inline fuses. I had planed to us a Tap-A-Fuse but it wouldn't fit properly. Both the wires run along the firewall to the passenger side of the van and through the grommet to below the dash behind the glovebox near the BCM. The third inline fuse seen in the photo is for trailer lights.

Everything under the dash gets tucked away behind existing wiring. The coil of wire in the upper left of the photo is for future use in the lower console. Neither the Lower console or the Rear circuit will have fuses installed at this time.

From under the dash two of the power circuits run up to the A pillar. One runs up the outside of the pillar and above the headliner to the hole near the rear view mirror. The other runs inside the A pillar to the top channel and to the rear of the van to be used at a later time.

I used an existing fastener to ground the relay.

This power socket is temporary, ultimately a socket will be mounted in the box part of the overhead console. Grounding is done at an existing threaded hole.

With the shelf reinstalled this was the first objective. When I turn on the van my radar detector is powered up. A Dash cam will probably come soon, maybe front and rear.

Special thanks to DonShockley for helping to source parts and wire.

[DonShockley]

Nice job. I especially like where you went directly to the bolt at the other end of the battery cable for constant power. I didn't realize there was a bolted connection under that cover. I had thought the taped connection to the battery cable was the only one in that area. Is the connection one piece with the bolt just holding it in place? Or is the metal for the high current junction box and the metal end on the cable two separate pieces held together at the bolt you used? What size ring terminal did you end up using for the connection? And did you have to modify the cover to allow room for the wires to exit or was the existing clearance sufficient?

I think I am going to have to modify my previous work once the weather improves this spring. Use another triple fuse connector with all 3 tied to that same bolt; one for my accessory fuse box, move the dealer installed hitch power to the second, and the third for future use.

I also like where you picked up switched power. I may be able to add one of the wires I stripped from the salvage fuse box I bought to add the other side of the fuse leg to the empty spot in the box and have the fuse installed there. But that will be wholly dependent on how easy it is to lift the fuse box up enough to remove the lower cover. If it's not accessible with relative ease, I'll use the tap like you did.

Edited January 18, 2016 by DonShockley

[Paul Hauser]

The ring connectors were 5/16. Getting that nut off and back on was one of the hardest part of this project, I unsnapped the plastic housing so I could pry it back a little. I'm not looking forward to replacing that battery. :( It seemed like the best place but I don't know if I'll be able to add much more there.

You could put two of those Delphi 6 way connectors back to back and use a common bar and jumper wires. I just soldered wires together to break out the power.

Let us know if you have any luck removing usable parts from the salvaged fuse block. That was my initial thought but I was to cheap to get on one Ebay not knowing if Id be able to use it.

[DonShockley]

......Let us know if you have any luck removing usable parts from the salvaged fuse block. That was my initial thought but I was to cheap to get on one Ebay not knowing if Id be able to use it.

I already stripped a bunch of connectors out right after I got it. I had hoped they would fit the Aux fuse box in the rear that I tapped into, but once I saw them it was obvious they were different. Getting them out is a real pain, but popping them in should be a cinch as long as I can snap the back cover off. The hardest part of getting them off is getting the white cover piece off. Each one has multiple tabs holding them on and you have to get them all to release. There's so little play in the covers that each tab tends to reattach itself as you work on the next one. Once the cover is off, you can stick a probe down to release the catch holding the terminal in. But putting them in just involves inserting them in the back of the empty spot until the catch clicks in place.

Edited January 18, 2016 by DonShockley

[Paul Hauser]

I finally installed the 12v sockets that are permanent.

one on each side as far forward as possible.

[avlisk]

I just bought a 2015 TC cargo van and have discovered that both 12v power outlets are hot all the time. That's rather inconvenient! Is there a simple mod to make them both hot only when driving? Like swapping some wires in the fuse panel? That's what I'm hoping for, as I'm not too technically oriented. Thanks in advance.