7 pin plug to 6 pin?

[grahambl]

What is the 7th pin for? I just bought a 5th wheel and it has a 7 pin on it, and everything else I have has 6 pin plugs. What will I be losing if I change it to a 6 pin



Thanks
Brian

[grt]

Short answer, Charging the trailer batt OR backup lights.

Typically you loose the charging wire. The one that will charge the batt in the trailer. Sometimes the center plug of the 6 is used to charge the battery, other times it used for backup lights.

With the 7 prong plug the center is "typically" the backup lights and the extra pin is the charge circut.

I built a pig tail for mine to go from a 6 on the truck to a 7 on the trailer and it works just fine, since I don't have backup lights on the trailer I really don't need all 7 wires. I don't know if it is "common" but it works for me and all the other trailers I've ever used it on.


On edit: if you change the RV plug to a 6 the yellow wire is usually the backup lights. (but if your luck is anything like mine you should probably verify)

[grahambl]

Never thought about backup lights! I will probably be changing mine to 6 pin if thatst he case, I dont have anything hooked to my center pin now but will hook up the batt wire




Thanks
Brian

[grt]

Hooking the batt wire to the center of the 6 worked for me. but some trailers wired with backup lights use the center prong for power. ITs not a problem but if you ever hook up to one of those trailers the backup lights will be on all the time.

I only had the problem once, its probably not a problem for you, I just thought I'd add it now so you don't end up scratching your head later like I did. [img]/ubbthreads/images/graemlins/smile.gif[/img]

[94_turbo]

get the adaptor--they dont cost much--and they work just fine--for a lot less hassle----------

[grahambl]

Do they make one that goes from a 6 pin (truck end) to a 7 pin (trailer end)? I have seen them the other way around?


Brian

[mgraveman]

you have to make those.

[AZExcursion]

Order here like I did.

http://www.hitchcorner.com/trailer_plugs.htm

look about 3/4 down the page at HC_6to7center and HC_6to7aux.

[img]/ubbthreads/images/graemlins/laugh.gif[/img]