I have a 2006 F150 Lariat SCAB - 4WD

I am trying to juice a switch (pressure switch) on the frame rail under the passenger side front seat.

Would be best if it were switched power.

If I could locate something under the hood in the area of the passenger/battery side...........that would probably be the best.

Or.....I could run something from the fuse panel inside the cab (if I can figure out how to get it out of the cab.......not much wiring experience here).

Any great ideas would be appreciated. The rest of the wiring is complete. I just need to find the best/easy way to juice the switch.

REST OF THE STORY
I am wiring in an air compressor and tank.
-The compressor is bolted down over the drivers side front fender next to the radiator/cooling system reservoir.
-Air tank is on the outside passenger frame rail. It's a 3 gallon tank with a pressure switch to turn the compressor on/off.
- Relay is hanging above the firewall on the passenger side of the engine.

This system will primarily feed a quick connect on the rear bumper next to the license plate

Totally worn out with the $30/$40 cigarette lighter compressors that can barely pump a bike tire or an air mattress. Even worse are the coin operated compressors at gas stations that are worthless......... and that's when they're not out-of-order.

 

First of all how many amps does it draw?

Based on what I will assume it will draw in amps, I suggest that you run a fused wire to the battery and use a switched source to trigger a relay to add safety to your system. Its a wise idea to have the compressor only come on when the truck is running. That safety will prevent a leak from leaving you stranded.

As far as wiring suggestions, the trigger wire can be tapped from near your fuse block and run through one of the two rubber grommets in the cab. One at the front and one at the rear. You can run your high current wire down the frame rail without too much difficulty. You should fuse this wire as close to the battery as you can for fire safety.

 

What is this wire for? To run to the pressure switch in the tank right? Is the other side of the pressure switch going to the relay for the compressor? If this is the case. Tap into your 12v ignition switch wire. This way the compressor can't run with out your ignition being in the "on" position. The wire you need is red and light green. It comes right off the computer.


And... while you have a air system...

 

I guess I need to be clearer for the best help.

All wiring is complete except for one wire.

WHAT IS THE WIRE FOR??
A low amp (switched) power feed to run to a pressure switch.

avfrog-------your suggestion should work. I will try and locate the red/light green ignition switch wire.

****************************************
Everything else is wired and ready to go.
Relay 30 - 30 amp fused feed from battery........done
Relay 87 - power to compressor...............done
Relay 85 - ground..............done
Relay 86 - pressure switch trigger............done
****************************************

 

^ it comes right off your computer into the main harness. This is where I tapped into with a T tap for my set up.

 

My pressure switch on my air tank has 2 prongs. This simply breaks the power feed to air compressor. Or you can use it to trigger a ground. So connect one prong to power or ground and the other to the power or ground of the compressor.

 

Got er did!! Thanks for all the help and suggestions.

Ended up hlln4whls suggestion...........ran a wire through a passenger side firewall grommet and tapped a fuse. Seemed easy in thought.........was a biach to get the wire through the grommet ..........other than that.....it's all good.

Hooked everything up.......turned on the ignition and.....wa la......it works.

Now to plumb the air line. That will be a cinch compared to the wiring.

Thanks again!!!!!!!

 

oh ok I got ya. You don't have a pressure switch you have a pressure relay.