finding a constant 12v source

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May 21, 2021 | 10:22 AM

Runflat

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4wd Low

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finding a constant 12v source

I have a 2019 f250 XL SCAB gasser. The cab is not very well lighted (the rear seat dome light is effectively useless) so I want to install some extra LEDs that are always available. There is a fuse box immediately forward of the pax front door and one under the hood near the firewall on the pax side. I can't find any "always-on" voltage in the pax compartment fuse box, but the box under the hood has plenty. The problem is that there is so much junk & so little space in the area of the under-hood fuse box, not to mention above the pax foot-well, that even running one small wire through the firewall in that area looks to be a nasty task that might even run the risk of damaging something.
Any suggestions?
Tx

May 21, 2021 | 10:54 AM

Ltngdrvr

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Straight to battery.
There are a number of places to pass wires through the firewall.

May 21, 2021 | 10:57 AM

shadowSVT

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Joined: Jan 2006

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From: So Cal

If you run a wire straight to the battery, make sure you fuse it a couple inches from the battery.

May 21, 2021 | 12:13 PM

ford390gashog

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Joined: Jan 2004

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From: Brentwood,CA

Well there is pass through wires to get to the battery if needed. I also believe there is a 12+ in the SEIC harness bundle.

May 21, 2021 | 03:41 PM

T. Banning

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From: MO

Quote:

Originally Posted by ford390gashog

Well there is pass through wires to get to the battery if needed. I also believe there is a 12+ in the SEIC harness bundle.

Unless you have the upfitter switches, I don't believe you'll have the passthrough wires!

May 21, 2021 | 05:26 PM

ford390gashog

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Joined: Jan 2004

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From: Brentwood,CA

Quote:

Originally Posted by T. Banning

Unless you have the upfitter switches, I don't believe you'll have the passthrough wires!

The pass through wires are on all superduty trucks.

May 21, 2021 | 06:06 PM

T. Banning

More Turbo

Joined: Dec 2013

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From: MO

Quote:

Originally Posted by ford390gashog

The pass through wires are on all superduty trucks.

I gotcha! I didn't realize that.

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May 26, 2021 | 08:09 AM

Runflat

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4wd Low

Joined: Oct 2019

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Quote:

Originally Posted by ford390gashog

Well there is pass through wires to get to the battery if needed. I also believe there is a 12+ in the SEIC harness bundle.

gashog,
Thanks much for the post--VERY helpful. The engine-side ends of those wires were bundled and pretty well hidden under the fuse box. I would have never found them without your images--and a mirror. These built in pass-through wires should work great. Now I can do a decent install & get power right from the weather-proof fuse box under the hood. And I don’t even need to remove a wheel well liners or screw around punching more holes through the firewall.
Thanks again!
RF