Best Way to Convert a 4-Way Round into a 7-Way RV Harness

Updated 12/14/2020 | Published 12/10/2020

Products Featured in This Question

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3471)

$118.67

Custer Trailer Connector Adapter - 4-Way Round to 4-Way Flat

(26)

$18.24

Question:

Need to change 4-way trailer connector to 7-way rv. The ETCB7 is correct except I dont have a 4-way flat plug. The existing wires go directly into the 4-way connector. I could cut the flat off the ETCB7 and crimp but hoped for an easier solution.

asked by: Brian R

Expert Reply:

It sounds like you have a 4-way round connector and are needing an upgrade to a 7-way connector.

You are correct in looking at the etrailer Universal Installation Kit, part # ETBC7, as the best way to get the 7-way. As for the splicing and wiring into your 4-way round, if you'd rather not do that, we do have an additional adapter that you can use to simplify things.

It's the Custer Trailer Connector Adapter, part # ADP001. This easily converts your 4-way round into the 4-way flat that the ETBC7 needs since we don't have a kit like the ETBC7 for 4-way rounds. I've linked to a video review of this adapter for you to look at.

Of course, I still recommend the splicing option as that eliminates the "adaptor to an adaptor" setup which is not as secure as hardwiring. As easy and secure as the Custor Adapter will be, it's still always safer to eliminate any additional pieces if possible.

expert reply by: Kef G