When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Does anyone know a good source in the engine bay to tap into 12v switched power?
im wiring my power for the roof rack and other stuff and wanted to pull 12v switched power to runs a continuous duty solenoid. I THOUGHTi had a good source up by the passenger headlight but when I tapped in and powered the car it threw about a thousand errors and said the traction control, terrain response and a bunch of other suspension related items were unavailable but that I could drive the car carefully. It would go into park or reverse but wouldn’t actually drive.
it was the scariest goddamn thing because I thought I broke my wife’s truck good. And because it means that one wire getting cut could completely immobilize the whole damn truck.
tldr: it’s back together and fine now but I still need a good source of 12v switched power inside the engine bay. Figured I’d ask before pinning out a thousand more things (and doing it the right way not guessing)
Take a look at the above thread ... pretty far into the thread 2oolander self-installed a switchable line for his winch install.
The JLR OEM version has the owner tying into a winch power line which is auto-switched, to keep the winch and starter from being used at the same time. That detail can be found in one of the five winch install videos posted on PowerfulUKLtd.com
I do not recall seeing in any other New Defender thread any successful direction or success in wiring .....
Last edited by TrioLRowner; 01-26-2021 at 11:34 AM.
Thanks. The winch install is pretty much exactly the same way (and location) I did my roof light wiring. Except instead of a battery disconnect I went with a continuous solenoid so I need switched power instead of a manual Disconnect.
I found a few good sources for 12v power I’m under the dash but they’re all tied to the dash light dimmer switch so if I wanted to dim the lights on the dash, at the Lowest setting, it’s not enough juice to power the continuous solenoid. I’ll still probably go with one of those splices unless I find something better.
There looks like a service plug up under the dash between the brake and gas pedals. It’s got some pretty thick wires so I’ll check that for switches 12v too since it’s unused.
last thing I need to do is find a way to get my wires through the firewall and into the engine from the switch and I’m all set to go.
Ok. So I owe an update to this thread for anyone who’s trying to wire roof rack lights. Mine are finally all sorted.
The best way to pass power from the engine bay to the interior is through a big *** grommet above the steering column. You need to remove the windshield valence to get to any of this stuff and make your life easier with wiring too. So that means you have to yank the wiper arms.
the 12v switched power I picked up was off the back of the parking brake plug. The blue and white striped wire to the far right is 12v switched power but only when the head lights are on. So that’s good. Means you won’t leave your roof rack lights on in the middle of the damn day.
I used the dimmer switch location to mount three switches sideways and I’m really happy with how they came out. Had I known I’d be mounting them sideways I could have ordered them with the words oriented sideways, but I had no clue at the time.
my power distribution came off the accessory mega fuse in the engine bay then went to a fuse and relay block them through the firewall and into the drivers compartment. All in all I’m really happy with how it turned out. I’ve also got a continuous duty solenoid so there’s no parasitic drain on the truck from the accessories when the truck isn’t keyed on.
Engine Bay Fuse B9 is switched power (turns on with ignition on and off with door lock after ignition off). I used it to wire the remote for a Trigger 4 Plus lighting controller. Works great for my ditch lights and soon for a front light bar on my 2023 D90 P400
I know this is an old-ish thread with a recent victory, so I'll throw my 2-cents in based on all the hacking I've done to my Defender over the last year+.
Best place to get power in the engine bay (straight off the power line w/ minimal disruption) is the proscribed spot on the front right of the engine compartment. See Posts #11 and Post #12 from this thread for better pics and intel (Link).
Inside the cabin, the best spot is to grab it right off the battery that sits under the seat.
If in the boot and you have an X-Dynamic, it can be taken from the appropriate controller. If anyone needs to know, tag this and I'll look it up. Or, just search and you can see several mods with details.
If you need a power condition (only on ignition, etc), then do a fuse tap. There's a fuse box in the engine bay, behind the glove box or in the boot. Again multiple sources depending on where you are.
To transfer a wire from the inside to the engine bay, the best route is thru the rubber grommet where the steering passes thru the firewall. But there's only ONE reason to do that. That's to get a GMRS or CB antennae thru. All other wires (imo) should be run thru a controller (Trigger-6 or Trigger-4 are my recommendations).
If you need a wire thru the rear, there are two choices: if you need access to the door (inside) then there's already a conduit you can use. Lots of videos re: dashcams re: how to do that.
If you need to wire to the exterior rear, the D-pillars are your way. There's a rubber grommet and layers of aluminum. Again, lots of posts about this (use "Advanced" Search for best results).
Anyone have any other access points used? I think I've ticked off the basics.
I know this is an old-ish thread with a recent victory, so I'll throw my 2-cents in based on all the hacking I've done to my Defender over the last year+.
Best place to get power in the engine bay (straight off the power line w/ minimal disruption) is the proscribed spot on the front right of the engine compartment. See Posts #11 and Post #12 from this thread for better pics and intel (Link).
Inside the cabin, the best spot is to grab it right off the battery that sits under the seat.
If in the boot and you have an X-Dynamic, it can be taken from the appropriate controller. If anyone needs to know, tag this and I'll look it up. Or, just search and you can see several mods with details.
If you need a power condition (only on ignition, etc), then do a fuse tap. There's a fuse box in the engine bay, behind the glove box or in the boot. Again multiple sources depending on where you are.
To transfer a wire from the inside to the engine bay, the best route is thru the rubber grommet where the steering passes thru the firewall. But there's only ONE reason to do that. That's to get a GMRS or CB antennae thru. All other wires (imo) should be run thru a controller (Trigger-6 or Trigger-4 are my recommendations).
If you need a wire thru the rear, there are two choices: if you need access to the door (inside) then there's already a conduit you can use. Lots of videos re: dashcams re: how to do that.
If you need to wire to the exterior rear, the D-pillars are your way. There's a rubber grommet and layers of aluminum. Again, lots of posts about this (use "Advanced" Search for best results).
Anyone have any other access points used? I think I've ticked off the basics.
01-25-2021, 08:22 PM
12v switched power?
