4-Way Wiring for 1986 Ford F-250
Updated 12/15/2025 | Published 11/23/2024
Question:
Greetings, my 86 f250 has a four pole relay mounted far right on firewall. Appears to be for trailer lights, truck has original tow pkg. Can you get the relay, I have been looking w/no luck. Thanks, Geoff
asked by: Geoffrey L
Expert Reply:
Hi Geoffrey; the only 4-way wiring harness we have for your 1986 Ford F-250 is the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # HM40115. This is designed to fit the factory wiring connector so take a look at the connector and see if it matches what you have on your truck. I went ahead and attached a diagram below from the installation instructions so you can check for this connection behind the rear bumper if the other connector doesn't match.
(click to enlarge)
Product Page this Question was Asked From
Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- Hopkins
more information >
Featured Help Information
Instructions
Continue Researching
- Q&A: Trailer Wiring for 1986 Ford F-150 that Uses Spade Connectors for Connection
- Q&A: Receiver Hitch Recommendation for 1986 Ford F-150 with Step Bumper
- Q&A: Wiring and Brake Controller Needed for 1996 Ford F-150 with 4-Way Flat
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Article: Types of Bumpers
- Q&A: Parts Needed To Install 7-way Connector In 1984 Ford F-150 4x4
- Q&A: What Brake Fluid Should be Used in Surge Brake Actuators
- Q&A: Replacement for Dexter 34044 Hydraulic Disc Brake Actuating Trailer Brake Coupler
- Q&A: Best RV Rated Cargo Carrier Option for Cooler, Generator and Bikes
- Article: Brake Controller Installation: Starting from Scratch
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
Robin H.
12/15/2025
Hey Geoff, did the Hopkins 4-way wiring harness end up matching the connector on your F-250? Knowing how that fit worked out could help others trying to track down the right trailer light connection on older trucks.