Power tap location?

[SoCalChris]

I tried posting this in the Express forum about a week ago, but haven't gotten any replies so I'm trying again here. I'm adding a 12v outlet to the back of my van and a USB charger to each row of passenger seating, where would be the best place to tap to get power from? Preferably switched with ACC, but I'd take always hot too.

The upfitter manual says

Accessory Power Supply Feeds

For power requirements to service additional devices to be added by body builder/upfitter, the power supply source must be from the studs on the underhood electrical center mounted on the left hand shear wall in the engine compartment.

A junction block has been provided behind the drivers side B pillar. Both switched and unswitched power junction terminals are available (See Owners Manual for compatibility). All additional loads should utilize these terminals.

The only studs I saw under the hood near an electrical center was where a 125A fuse was attached. I tore apart the trim around the b pillar on the driver's side and the only thing there was the seat belt.

Any suggestions would be appreciated, I'd rather not wire this directly to the battery.

Thanks

[citydriver]

Not being familiar with the vans electrical system layout, I checked the wiring diagrams in the up fitter and found:

12 Volt Power Outlet Receptacle

Description and Operation

The accessory power receptacles and cigarette lighter

receptacle are supplied with battery voltage when the

ignition is ON or in the accessory position

 

I would verify this, then either tap those wires behind the cigarette lighter, or use the +12v power wire to trigger a relay that gets its power from the underhood electrical center. Again, I'm not familiar with the late model vans, but that junction block behind the "b" pillar may be behind the side wall trim panel near the pillar. I wouldn't hook the USB ports directly to the battery as they typically do create a parasitic draw even when they are not in use. Good luck.

[SoCalChris]

Thanks for the reply. The 12v ports in the dash are always on, not switched. I'm unaware of any other 12v power ports, but I'll check again. As far as the junction block, I removed all of the trim and found nothing, just the retractor for the seat belt. There's a fuse block under the driver's seat, but I don't see any spots to add new circuits to.

[HagiborChayil]

what year Chevy Express??? that would answer the question as we can then decide if we go to the Ignition switch or the BCM.

 

Ok, Edit now that I know how to use this forum and it says the vehicle right below your name....

there are a few different options depending on the options you had installed. if you have power door locks there should be a heavy gauge green wire, probably 12ga or 14 ga in the connector that is going into the drivers door.

 

otherwise on the drivers fuse box under drivers seat there is a heavy gauge green wire there that generally populates. be sure to use a multimeter to verify your wires! dont want to tap into something that doesnt work.