Hi all, I just bought a 20" LED light bar to put on my bull bar on the front of my 05 Dakot SLT Club Cab. I also bought a prewired harness that i have pictured here.

I know I can easily wire up the harness and I can also switch out/upgrade the switch (which is something I was thinking about doing) no problem. But if I can avoid drilling into the dash and using an existing switch I would prefer that but I don't want them to come on with the headlights or the foglights.

My question is there a way to bypass the switch and have the LED bar come on when I hit the cargo light button on my dash. I do not have a cargo light and I see there is a fuse for the cargo light in the fuse box. Can I wire this up using an add a fuse? If so what positivewire would go into the add a fuse? And what would I do with the wires that go to the switch if I were to remove it?

I appreciate any help or comments. harness.jpg

 

I'm no electrician, but i am familiar with electronics. But part of my Computer Science Engineering diploma included some electronics courses right up to the point of building an 8088 and an EEPROM burner so we can program it.

Anyways, something seems strange if you ask me. looks like that wiring uses the same power for the switch as it does for the light. Normally, you use a low power voltage for the switch, and the lights get direct battery power (fused of course) on the other side of the relay. This diagram seems very strange.

The switch also has 3 wires going into it, and it shows an on/off only. So unless the switch itself is also illuminated, then it doesn't make much sense to have the extra wires that go there. And even there, the illumination could use the same power signal that you would use to power the low side of the relay.

If i were you, i would use the switch that came with it since it's pre-wired for your light bar, and obviously, it works for the manufacturer. Instead of cutting into the dash to mount the switch, use that empty hole between the 4x4 and power plug in the dash. I don't know if the 05 has it, but the 07 my old job had it and my 11 has it. Make a little plate that you can mount in there, drill into that plate and mount the switch there.

I'm looking to add switches there for my lights once i get a chance to swap the bumper and add the lights i want to do.

 

The switch is pretty cheap and flimsy honestly but the rest of the harness is pretty good. It was only 15 bucks on Amazon and to be honest I am not sure I could make one cheaper or if I really have the time to. It is in fact illuminated and the problem with this switch is that it has an on and and off light so it is always lit even while the truck is off. I purchased another rocker switch to replace it and it to has three prongs as well.

Several people who reviewed the harness swapped out the switch and this is what they said about the three wires running to the relay. "the white wire is hot, the blue one sends power to the relay to turn the lights on, and the black wire is common ground."

Not sure if that clears things up but I really don't want to use the switch it came with and like I said I can swap it out no problem but I am wondering if I can somehow tap into that fuse that goes to the cargo lamp button on the dash.

 

I will look into that plate you mentioned though by the lighter. I may recall seeing an open space there. It is not a 4x4 but i don't think that matters. Thanks.

 

Most 12v Switches illumination require a ground wire, not + to ground the LED, It uses the same 12v + as the incoming one.
+ Input (From Battery) Powers Output and LED
- Ground (LED)
+ Output (To Light)
This is what every Auto switch ive seen is.


There is no empty hole on my 05, it has a Pass air-bag on/off switch. and a chubby hole where the 4x4 would be.
I have my 21" LED Light bar wired direct thru my switch, Have not had it installed long.
Mine has 14 gauge wire, Goes Battery Positive - Fuse holder (By Battery) - Switch then back out of cab to light, then the Negative is bolted to the frame from the light. Same for my SWS Strobe Beacon. All my works trucks beacons are done the same (LED Ones)

 

My 40" I have wired using the included switch and just attached it under the dash using a piece of adhesive velcro. The tiny LED in the switch is really inconsequential to your truck as long as you aren't leaving it parked for months at a time.

 

Thanks for the info Reject. I like the roof mount light bar ODXBeef. What type of bracket is that that you used to mount it with? I may just swap out the cheap switch with one of the rockers I bought and just find somewhere to mount it. The included switch just feels very cheap to me and I don't see it lasting long. Thanks for all the feedback.

 

The idea of a switch and relay is to use the switch for low voltage, to close the armature of the relay and close the high voltage circuit, activating the accessory. The wiring diagram you provided looks just fine, and in fact, is the same diagram for factory switch, acc, relay, and fuse configurations. If you want to change the switch, label the three wires (ground, acc, 12v+), and select the three prong switch of choice.

 

I used to have relays when I ran higher-amp lights, (4x55w)

Relays like donkeypunch said keep the higher amps away from the switch, most switches are only rated for lower amps, and can burn up or burn out using higher amps.

Im thinking of changing my fuse, to a lower amp one to see how low it can go and not, instantly burn it out. I know 3.5A is to low haha, my old strobes had that when i hooked it to test the brightness before the new fuse holder and fuse last 2 seconds or so

 

That was my understanding about the relay as well DonkeyPunch. A lot of people talk about how hot their switches are and it is usually because they are not hooked to a relay. So do you think I could open pop out the switch panel that has my headlights, fog lights etc and just wire directly up to the leads on the back of the cargo light button?