rickyp

My 08 F150 came with a towing package. the truck has two plugs the 4 wire flat and the 7 wire round.

Can you use both plugs at the same time?

what what does the wires on the 7 round go to?

If I can use both plugs at the same time I am thinking about putting some "fog lights" on my trailer and wiring them to a 7 round plug so when the marker lights are on I can light up the back of my trailer with the fog lights.

nagata

Here's a site that gives a decent description of how the different wiring setups work (4-wire, 6-wire, & 7-wire). If you want extra functionality, I would recommend just rewiring your trailer to a 7-pin setup, rather than running two separate plugs.

Whoops, forgot to include the link: http://www.etrailer.com/faq_wiring.aspx

DLL66

I think you forgot to post the web site.

nagata

Hahaha, so I did...Edited as needed.

rickyp

thanks that was most helpful

the reason I am thinking about running 2 lines is: I have two trucks my Ford F150 that has the 7 wire and a Nissan frontier that has only the flat 4.

nagata

My recommendations for a solution to that situation would be to either create an adapter to step down from a 7-pin plug to a 4-pin plug or add a 7-pin plug to your Frontier. Depending on the model year of your Frontier, it may be as simple as buying the socket and plugging it in to the already existing harness. Bonus of putting a 7-pin socket on your Frontier would be that the trailer would have full functionality (the lights you want to add in your case) with both vehicles. Since your trailer originally had only 4-pin wiring, I'm assuming it has no electrically controlled brakes, meaning no worries (from a safety aspect) of stepping down to a 4-pin wiring setup that provides the basic lighting requirements.


*Disclaimer* In most circumstances, it is NOT okay to 'step-down' from a 7-pin plug to a 4-pin plug, as in many situations the 7-pin is there to control trailer brakes. I am not advocating/facilitating the modification of trailer wiring, make your own decisions about the feasability and safety of the modifcations in your own situation.

rickyp

If I put a 7 round plug on the trailer I was thinking about getting a 7 pin plug and mounting it to the trailer then where you would hook it to the truck just put a 4 wire plug on that end. this way I would plug the trailers 7 prong into the plug on the trailer then plug the 4 wire end into the Nissan. quick and simple. The Nissan's alternator will not handle the extra load of the lights and trailer lights.

My trailer is just a 3000 lb 6.5 x12' landscaping style trailer with a single axle. nothing great but works for me.

wakonako

So far as I know, you are not able to use both plugs at the same time.

The round 7-Pin plug has the same connections as the flat 4-Pin plug, but it used generally for the larger trailers that either have brakes, or extra lighting on them.

The 4-Pin connects to: Left brake, Right brake, Left blinker and Right blinker. Hence the 4 wires and 4 pins. On our dump trailer we have the 7-Pin, but the trailer also has brakes and extra running lights.

You can get adapters for your trucks though from like TSC that will plug in and change the configuration from 4 to 7 or the other way round