No running lights on boat trailer towed by 2008 ford f150

Check the bulbs and grounds at the trailers marker lights.

Troubleshooting No Running Lights on Trailer but Turn Signals and Brake...
http://www.mastercraft.com/teamtalk/archive/index.php/t-17703.html
Thread Running lights on trailer don work but turn signals and brakes do

There is a fuse box under the hood that has the fuses that control the wire harness. There are at least 2 boxes, mine were on the drivers side wheel well near the rear of the engine compartment.

If you have your owners manual it will be in there.

• Home
• Search
• Privacy Policy
• Contact Us
• Links

Trailer Wiring Diagrams 4 Way Systems

4 way flat molded connectors allow basic hookup for three lighting functions; right turn signal / stop light (green), left turn signal / stop light (yellow), taillight / license / side marker (brown) and a ground (white).

4 way tow vehicle side.
4 way trailer side.
5 Way Systems

Same as 4 way system listed above but adds a extra blue wire for brake signal or auxiliary power. Used on pop up camper trailers or utility / boat trailers.
5 way tow vehicle side.
5 way trailer side.
6 Way System, Rectangle Plug 3/4 inch by 1 inch 6 way rectangle connectors right turn signal (green), left turn signal (yellow), taillight (brown), ground (white). The red and blue wire can be used for brake control or auxiliary. Use on a small motorcycle trailer, snowmobile trailer or utility trailer. Can also be used as custom wiring on trailers with 3 light/wire systems. See "Tow Vehicle Taillight Wiring" below.
6 way tow vehicle side.
6 way trailer side.
6 Way Systems, Round Plug

Round 1 1/4" diameter metal connector allows 1 or 2 additional wiring and lighting functions such as back up lights, auxiliary 12v power or electric brakes. Note: The black (sometimes red) 12v and blue electric brakes wire may need to be reversed to suit the trailer. Check with a test light or VOM. Uses: horse trailer, travel trailers, landscaping trailer, car trailer, etc.

6 way tow vehicle side.
6 way trailer side.
7 Way Systems

Round 2" diameter connector allows additional pin for auxiliary 12 volt power or backup lights. Uses: heavy duty landscaping trailer, car trailer, boat trailers, horse trailer, travel trailer, construction trailer, etc. Check with a test light or VOM.

7 way RV flat blade tow vehicle side.
7 way RV flat blade trailer side.

Most likely the brown wire from the trailer connector is connected to a constant battery voltage source, and it should be connected to the vehicle running light circuit, however someone might have wired the trailer connector up that way on purpose so that the trailer does not draw power from the vehicle running lights and possibly damage the vehicle running light circuit. (Dodge/Chrysler vehicles do have delicate lighting systems) Here are some images to help assist you, and the 4 way connector is the same as the 5 way connector just without the blue wire for the trailer brakes.

If you have trailer lights make sure you don't have a short in the connector or harness. You obviously have a short somewhere after the fuse. Try unlpugging each running light. to see if its in the light connecter. also check the side markers

If you have amber signal lights & red brake lights, it's 2 separate circuits. You'll need to buy a small converter that you wire into harness to correct that. Not expensive, try autoparts store or RV/trailer sales, should have them.

Battery junction box (BJB) fuse(s):

• 5 (30A) (trailer electric brake controller)
• 34 (25A) (trailer tow turn relays)
• 42 (30A) (trailer tow parking lamps)
• 44 (30A) (trailer tow battery charge relay switch side)
• 63 (15A) (trailer tow reversing lamps

I take it the blinkers and brake lights work ok when not hooked up to the trailer? If yes, then the wiring to the tow hitch is not hooked up correctly. How many wires to trailer pig tail connection? U can have up to 7 depending on what you tow. Check to make sure these wires are hooked up from the truck to tow plug correctly: 7 wired---
brown-Rt turn and brake light, yellow-backup, white-ground, blue-electric brake, green-tail running lights, black-battery charger, red-left turn signal and brake light. Let me know if u have something other than 7 wire, I'll get the wiring color and source info for u.