Can I Use The ZCI Harness 119250KIT To Combine Tail Lights On A Semi?

Question:

I am wanting to wire my 2017 Volvo VNL Semi-Trailer to my 2022 PrimeTime 5th Wheel. I know that I will need a taillight converter since my Semi-Trailer turn signal and brake light run on separate circuit, while my 5th Wheels turn signal and brake lights run on the same circuit. Would this product work for my Semi to 5th Wheel wiring conversion? Thanks

asked by: Jack

Expert Reply:

Yes, you can indeed use the ZCI Circuit Protected Vehicle Wiring Harness # 119250KIT to combine the tail lights on the semi. We actually recommend this product quite frequently for this purpose. To install the actual RV 7-way use install kit # ETBC7 which will include everything to install the 7-way and a brake controller. For a brake controller I recommend using the Tekonsha Prodigy P3 # 90195 since it is their most user-friendly and durable controller.

You may need additional wire and for that we have # 16-4B-1 for 16 gauge 4-wire and # 12-1-1 for the primary 12-gauge wire.

I have linked some wiring diagrams below which you may find useful.

expert reply by: Jesse M

Jack

2/23/2024

Thank you! Have you had any success stories from people who have used this for semi to rv applications?

Jesse M.

2/26/2024

@Jack oh yes absolutely. We do not deal with a lot of semi related stuff here, but this is actually a question we get quite a bit, so you are definitely not the first person to attempt this. In my opinion using the ZCI harness and the ETBC7 kit is the most "by the book" way of adding a 7-way. And it will bypass the existing wiring, so you will be set up to tow a semi trailer or a 5th wheel.