Tow mirror wiring

Help. Very frustrating. 2018 sr5. Installed after market tow mirrors. Plug and play, except for the spotlights. Each mirror has hot wire and ground wire for the spotlights. Grounded both mirrors to the bolt by the kick panel.
Truck already has bed lights wired to cargo lamp switch. I want to wire the mirror spotlights to the same switch. Shouldn't this be as simple as using a T tap to connect the mirror hot wires to the same wire that the bed lights are tapped into on the back of the cargo lamp switch? That's not working. Please help.

 

The puddle lights in my mirrors are wired in the same way. Grounded to the bolt on the a pillar lower kick panel on each side, power coming from the cargo light circuit.

First thing I would do is use a piece of wire to quickly jump your positive wire to the battery. The ground should be good. Do this quickly to make sure you are wired properly and putting 12v down the positive wire does in fact turn the light on. You just need to touch it to the battery post for a few seconds really quick.

I am not sure how your bed lights are wired into the circuit but the cargo light switch just controls a relay that sends power to the cargo light. To do this the right wire you need to tap into the power going to the cargo light bulb from the relay, not the back of the switch.

Here is the Cargo light diagram. Based on the Cargo Light Switch, Door Switch, the Body ECU powers or unpowers the relay connected to the cargo light. IF the relay is energized the Cargo Light will be lit, if not energized the cargo light should not be lit.

The pink wire is the one you want to be on. If the cargo light is ON it should have 12V, if its off pink wire will be 0V (No power).

FYI if you are on the blue wire you are on the wrong side of the "switch/relay". The blue wire is connected directly to the battery via the Cargo fuse and will be hot at all times no matter what.






Look under the drivers side dash in the body control module. (Same box the interior fuses are in).

On one side of the box you should see 4 connectors looking like these. The top one connector 3K on Pin #28 should be the pink wire. If you tap into this one for hot or power to your lights and make sure they are grounded good it should be working correctly. They will light up when you unlock the truck, go off when you lock it or close the door the same as the Cargo light in the back.

 

Jeff_5_7 you saved the day! Thanks for the detailed explanation. I've read other threads on this topic but your explanation was the first one that I really understood.
I tapped into the pink wire under the driver side door sill. The lights work great and function the same as the cargo light and bed lights.
I still don't understand how the bed lights are wired in between the switch and the relay, but they work.
Thanks for the help!

 

They maybe setup similar to the cargo light circuit. Bed lights on a relay that is triggered by the switch.

Find where the power wire from the lights is going and that will give a better idea how the bed lights are activated.

 

I’m thinking/betting the bed lights are tapping their power off a live power source and are grounding through the violet wire on the cargo lamp switch that eventually tires back to the ECU. There are a lot of low amp circuits in the truck that operate this way. I’d have to go back and re-look at what my factory bed lights were set up to do.

 

I was assuming the same. The circuit is using the cargo switch for a ground trigger to power the lights. IF aftermarket installed this should be fine as long as it has a fuse on the power wire. The lights would have power 24/7 and only come one when the cargo switch grounds them out to complete the circuit.

 

Hello sir, how do I ground the wire to the spot lights if it only has positive white wire coming from them?

 

Thanks Jeff 5_7 followed your instructions and got mine wired up. Appreciate the help

 

Welcome to the forum..