Running wire from the 12V battery to back of car

I just bought a Curt trailer wiring converter and it requires that I run a power wire all the way from the positive terminal of the battery to the back of the car where the module is going to be located. They give no specifics on how to run this wire. How to I get the wire through from the trim at the bottom of the driver's door into the "engine" compartment?

Most trailer wiring uses the rear lights.

I know, but this one uses direct battery power, as well as tapping into the rear light harnesses.

I was successful with this exact project!

No pics for you but i was able to poke thru a rubber grommet directly behind the 12 volt battery. not easy to see from the 'engine' bay but pretty easy to see and poke a stiff wire thru from the driver's underdash perspective.

It is a grommet with wires already in it so do be careful. I used to do this sort of thing in a past life so have a bit of experience. I'm no more help than that without pictures I'm afraid.

Others have gone thru an empty grommet on the passenger side. Try searching for Lasereth (spelling?) stereo install here on MNF. Although searching using Google works MUCH better than the internal search here.

I have not looked over there but may in the future for a potential subwoofer/amp project (larger gauge wire).

Curt

A big thanks! I'll see what I can find. This penetration location would also be useful info to know since I always wanted to run a wire to hook to a kill switch for the motion whistle speaker which is kind of annoying sometimes, but I'll keep the noise on in places where safety warrants it.

wow there's no way I'm getting through that grommet, it's super tight. I love how the instructions for the trailer wiring are all so specific, except of course on how to run the wire to the front of the car, providing no guidance and only the statement that it will be different for every car. Well yeah.... wondering if I should just return it and get one that doesn't need to run this wire.

You can also look for an always-on circuit to tap into that's under the dash inside the cabin. If the fusebox is inside on your car, there should be an available tap there.

LeftieBiker said:

You can also look for an always-on circuit to tap into that's under the dash inside the cabin. If the fusebox is inside on your car, there should be an available tap there.

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Actually I found the fusebox to the left of the dash while taking off some panelling. I will try that, thanks

Don't forget to either use a spare fused tap, or an inline fuse in the new cable.

http://www.salsleaf.com/leaf_stereo/index.htm

See if these pics help for the passenger side grommet.

This is the MNL thread:

http://www.mynissanleaf.com/viewtopic.php?f=36&t=14156

Lasareath is the user name who did all this.

Curt

MarkBC said:

wow there's no way I'm getting through that grommet, it's super tight. I love how the instructions for the trailer wiring are all so specific, except of course on how to run the wire to the front of the car, providing no guidance and only the statement that it will be different for every car. Well yeah.... wondering if I should just return it and get one that doesn't need to run this wire.

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Yes- get another solution, running a wire like that seems senseless for a trailer and you risk damage to the car. Plug you are not supposed to connect directly to the battery terminal on a LEAF + I believe.

Basically you do not go through the grommet proper. I use a sharpened length of a 50 ft wire fish tape. It is around 3 ft long. I push it over or under the main wires but close enough that I clear the grommet hole metal. After it goes through I firmly tape the wire to the fish tape. I then pull the wire through. It is easier to do than describe. Fifty years of doing installs makes it second nature to me.

Yeah that seems strange to wire to the battery. I don't get these add-a-circuits. I don't understand how you can add an additional fuse to an existing circuit without screwing up the circuit you are adding to.

MarkBC said:

Yeah that seems strange to wire to the battery. I don't get these add-a-circuits. I don't understand how you can add an additional fuse to an existing circuit without screwing up the circuit you are adding to.

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If you add to an existing circuit you have to make sure it has lots of extra capacity, but it's better to find an unused space in the box. The middle option would be to tap into the main fusebox connection, installing an inline fuse of the correct amperage in the vicinity.

MarkBC said:

.... wondering if I should just return it and get one that doesn't need to run this wire.

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I would not recommend doing that. The power provided to the tail lights, turn signals etc. in a car like the LEAF won't be enough to power the lights on the trailer and the thing you bought also isolates the power sent to the trailer (or whatever lights are on the back side of it) protecting them from problems in the trailer wiring. A bit of a pain to install, but you will find will be well worth that effort.

jpadc said:

I would not recommend doing that.

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I agree. I got an add-a-circuit and I should be able to tap into the fuse box on left of dashboard so I shouldn't have to poke through the firewall. But I still have to rip up all the panelling to the back to run the wire, a bit of a pain.

I seem to recall that all of the constant voltage fuses were under the hood. I think all of the inside ones are switched.

I agree to use alternate power. The reason I would recommend using alternate power is if the brake lights short out on the trailer, it will blow the fuse for your main brake lights and you will have no brake lights at all. The same thing would happen with your running lights and blinkers. Your better off using an alternate power source to avoid loosing the lights on the vehicle as well.

EVDRIVER said:

Plug you are not supposed to connect directly to the battery terminal on a LEAF + I believe.

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That's the negative terminal. The positive terminal is perfectly fine to connect too. But the negative terminal on the battery should not be used.

MarkBC said:

Yeah that seems strange to wire to the battery. I don't get these add-a-circuits. I don't understand how you can add an additional fuse to an existing circuit without screwing up the circuit you are adding to.

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So in the fuse box the fuse has two pins. One pin goes to the circuit being powered and one is the source of the power. With one of the add a fuse things it replaces the fuse. Then it allows two fuses to be connected. Each of those fuses is connected to the fuse boxes source of power pin. Then one of the fuses is connected to the fuse boxes original circuit being powered. Then the second fuse is connected to a wire/etc for the new circuit. They are a pretty great design that makes adding new fuses easily without modifying the cars wiring/going to the battery/etc.