electrical wiring question for aftermarket rear bumper lights

Looking for some wiring advice for those with electrical wiring scheme experience.

I recently mounted Rigid Industries Flush mount D-Series into my aftermarket steel bumper and installed a relay with on/off power (#86 in pic) coming from the reverse lights wire in the trailer harness so the lights illuminate when backing up. The set up works great and have #30 connected to a fused battery feed.

My question:
I would also like to wire into the scheme an on/off source from the OEM cargo light so my rear bumper lights illuminate using the cargo light switch in the dash (I already know which wire to tap).

Can I tap into the cargo light switch wire and add it to #86 IN ADDITION to the reverse light wire coming from the trailer harness without causing a potential electrical short? Is a diode necessary so not to send electrical current back to the cargo switch when the reverse lights are on?

My goal is have the lights illuminate when backing up AND when the OEM cargo light switch is turned on.

THANKS!

 

If the wire coming from the cargo light switch is +12v when on, you can do it with a couple of diodes. Something like a simple 4001 diode would work. You would put one on the wire coming from the cargo switch light and one on the wire coming from the reverse lights. The stripe towards the relay terminal. Both hooked up to terminal 86.

Otherwise, regardless of the cargo light switch polarity, you can also just use another relay. Hook it up just like the one that you have, and connect both the relay's 87 pins to the positive feed on the Rigid lights.

 

P.S. 20 awg wire to the relay pin 86 and diodes...
Or better tap red #5 on IA4 for reverse feed
And Cargo Lamp feed on IE1 #14

 

Thanks guys!

 

Finally got around to wiring the Rigid LED's into both the cargo light and reverse light feed. Added 2 diodes to the scheme as recommended and success!

Rear bumper LED's illuminate either when in reverse, when the cargo light is automatically on or when I turn "on" the cargo light switch. So much more functional than just wiring to a toggle switch. Love it when a plan comes together. Thanks for the help guys.

 

Looks good. I did mine this week too. Mine come on when in reverse or with an OEM style switch on the dash. I didn't bother with the diode, because I was OK with the switch causing both sets of backup lights to come on.

 

Excited because I'm a DIY'er but have held back on electrical projects. I think learning about diodes and how electrical schemes work was more exciting than the bumper LED's. So cool when there is a theory or plan, you do it and it works.