Ot:Wiring question??

[SJK2]

Might not be right forum if so Mods pls move:

I have a 2000 ford expedition w/factory tow pkg:

pins 1-6 are all wired up for trailer all is well

I want to add 12v to spare pin #7 for accessories inside trailer can I tap pin
# 4 +12v battery charge or is there a better source???

Tia,
Steve

[trularin]

They guy who buys the vehicle from you will probably hate you.

May I suggest a 12V seperate terminal?

[SJK2]

Originally Posted by trularin

They guy who buys the vehicle from you will probably hate you.

May I suggest a 12V seperate terminal?

Maybe im not stating correctly my trailer is wired on pin 7 for inside lights I want my truck side to be same; ie pin 7 needs 12v

Steve

[vettestr]

Steve,
You can add 12 VDC to a pin for charging your trailer battery during the tow. NOTE #### the plug used for this on trailers is about 3" in diameter and not a 1 to 1 1/2 small plug used for standard towing applications. The smaller plug is not intended to carry the amperage and will not be wired on truck side for this application.
The better way is to get a RV or Trailer plug if you do not have one rated for amperage. See http://www.rverscorner.com/wiring/7pole.html .
Use proper wire gauge for power and ground directly to a battery source not fuse panel. Also install a battery ISOLATOR http://www.pplmotorhomes.com/parts/r...y-isolator.htm that will keep trailer from draining truck battery when parked.
HAVE FUN !!!!!

[SJK2]

Originally Posted by vettestr

Steve,
You can add 12 VDC to a pin for charging your trailer battery during the tow. NOTE #### the plug used for this on trailers is about 3" in diameter and not a 1 to 1 1/2 small plug used for standard towing applications. The smaller plug is not intended to carry the amperage and will not be wired on truck side for this application.
The better way is to get a RV or Trailer plug if you do not have one rated for amperage. See http://www.rverscorner.com/wiring/7pole.html .
Use proper wire gauge for power and ground directly to a battery source not fuse panel. Also install a battery ISOLATOR http://www.pplmotorhomes.com/parts/r...y-isolator.htm that will keep trailer from draining truck battery when parked.
HAVE FUN !!!!!

Maybe im not stating correctly:
Both my truck and trailer have a standard 7pin connector wired:

Truck
Pin 1=Grnd
pin 2=Elec break
pin 3=tail/running lights
pin 4= + 12v battery charge
pin 5=left turn/stop
pin 6=right turn/stop
pin 7=spare

Trailer

Pin 1=Grnd
pin 2=Elec break
pin 3=tail/running lights
pin 4= + 12v battery charge
pin 5=left turn/stop
pin 6=right turn/stop
pin 7= inside trailer lights

How can I get +12volts to pin 7 on my truck ???

[vettestr]

Steve,
I am not being a smart a$$ here but (If you hook up a wire from a 12 VDC source on one end then hook up other end to pin 7 on the truck side you will have what you are asking for).
Point I was trying to make was to keep from potential damage if ever used by ANY other person = truck = tow truck etc... and wired different than the Standard then a possible problem but adding voltage to a spare pin is probably a safe bet. I might suggest you hook up to pin # 4 that is now the charge or supply voltage. Again I stress the isolator so it will not drain tow truck when not in a charging state or condition.
So it will supply voltage when parked folks add series connected 6 VDC batteries in the trailer to run off of or add a second 12VDC tow truck battery with isolator between that battery and tow rig for starting reasons. The tow battery will not last a real long time without charge so that is why the series 6 VDC are so popular.

[SJK2]

Ok Jeff sounds like what i want.......

Thanks.......

Steve.....

[vettestr]

Thinking about the thread more it came to me that you propably have an isolator now that removes power to trailer when tow rig is not running. Thus the problem is how to get power when parked +++++.
Add a tow rig battery and pull from it or add trailer batteries (that is the best) and pull from them. When they are low you can start tow rig to charge the trailer. If you defeat the isolator bad things will happen sooner or later as a rule. New cars with computers do not like voltage hits and sags so fight temptation to defeat the isolator. buy more batteries as cheaper than repair costs to tow rig.

[SJK2]

Originally Posted by vettestr

I might suggest you hook up to pin # 4 that is now the charge or supply voltage. .

This was mainly the question as to if i could bridge pin 4. The pin 7 trailer inside lights are only for night loading and they are on a wall switch. And i do have a 12v trailer batt on the tongue powered by pin 4.....

Steve