Factory Switched 12 V power diagram needed

Im installing a 12 V outlet under the drivers seat to plug in a we-boost. I have a power tray in the engine bay, I have a 4 pin relay, I have a oem style on/off switch for the dash (with illumination). Can anyone direct me to a wiring diagram to make all this happen?

 

I don't have a diagram or schematic, but I do a similar setup in my 4Runner and other vehicles for communications equipment.
Here's how I do it:

• Use the under dash fuse block to source your "switched" power. The fuse position that serves the radio works well. Use a blade fuse tap with its own fuse. Route that to your OEM style switch terminal.
• Wire the other OEM terminal through the firewall (there is a removable, nipple-like, grommet on the firewall. It's easier to find on the engine side of the firewall. It will be on the driver side, above where the main wiring loom enters the firewall). This will go to the "+" connector on the relay coil. The "-" connector on the relay coil goes to either the negative terminal of the battery or to the chassis ground.
• Wire a fused lead from the positive battery terminal to base terminal ("B" in the drawing) of the relay, and wire the pole terminal ("A" in the drawing) through the firewall. Run this lead either under the carpet or through the driver side kick panel, then under the door jamb molding to your plug or distribution terminal under the seat.

I've found it much easier to first run the wires from the engine side of the firewall to the driver side. The access hole is not easy to reach from the driver side. A straightened wire coat hanger with the two wires taped to the end makes a very good insertion tool.

 

Thanks! This is what I just sketched up….does it look correct? My only concern is I have a couple add a fuses for other accessories like my garmin dash cam in the fuse box already and not sure if I can physically fit another add a fuse and not sure if I can tap into an existing add a fuse.

 

Hey that schematic looks pretty good, at a quick glance.

I've wired decent amount of 12v offroad lighting and KDSS control switch, all w/ OEM style dash switches. Some are energized from interior fuse slots, others direct from battery - kinda cheated and used premade over the counter wire harnesses that include light connector(s), inline relay, fuse in a holder, non OEM illuminated on/off switch.

This video, and similar vids, and offroad lighting vids helped me in the right direct for power sources and illumination wires to tap to:
https://youtu.be/UMmqE8CKRfE

 

battery fuses relays

 

Maybe Im misunderstanding the intent here but is the switch topmost blade (C line) going to fused power from the radio just for the illumination power? And then youve also got a tap into the dash illumination (R2 line)? So there are two ignition controlled sources going into the switch? What exactly is the switch doing then? If you want it ignition controlled you could just route the tap from the radio directly into the 86 pin on the relay so that the plug powering the Weboost only has power when the ignition is on.

 

My end goal is to have a 12V outlet that can be turned on or off if the car is on or not running. So constant 12 V power that is interrupted by the switch is what Im hoping to accomplish.

 

Referring to your diagram, why couldn’t the wire coming from the radio fuse to the C terminal on the OEM-style switch instead come from any unswitched source? You could bring it in through the firewall and avoid the traffic jam with the add-a-fuses at the footwell fuse block.

 

That is a great idea. Especially since I just installed a blue sea fuse block in the engine bay.

 

This version, using a 5-pin relay, allows the outlet to be powered by either a switched or unswitched source.

OEM style switch in OFF position (open): switched current flows to terminal 87a on the relay. 87a and 30 are normally closed, so that switched power goes to the outlet. On when the car is running, off when it’s not.

OEM style switch in ON position (closed): relay is energized and now the outlet will get power from an unswitched source regardless if the engine running or not.

 

Not sure I fully understand your diagram. So the 12V unswitched is direct to the battery? What does the 12V switched go to? Will my original diagram work? I also just saw that instead of grounding the switch to the grounding block in the footwell, most people tap into the variable grounding wire from an adjacent switch.

 

I think the schematic looks good. I would add a fuse between the 12v outlet and the relay, just for safety. The value of this fuse should be lower than the value of the fuse between the relay and the battery.
And, since you are going to the trouble of wiring, I would also add a terminal/distribution block (see below). This will give you room for expansion circuits, and each circuit leg has its own fuse. I've don this in my vehicle. Feed it with 10 ga wire from the relay to give you adequate current capacity.

 

I don’t know what you’ve got going on with your fuse block. (Looks good by the way,) but you could connect the unswitched power to the fuse block. If you have a switched source at the fuse block too, you could wire the inswitched source there, or to an add-a-tap in the fuse box under the hood.

Your diagram above will work provided that the fuse that sends power to the switch, the one you’ve labeled Radio Fuse, is unswitched.