Need Help on trailer plug

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May 7, 2008 | 06:18 AM

racin87

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From: Humboldt,IL.

Need Help on trailer plug

I figured out how to get power for the trailer brakes (fuse).But can not figure out how to get the 12 volts back to the plug that powers the interior lights on our enclosed trailer.

Help would be GREAT thanx in advance,Chuck

May 7, 2008 | 07:24 AM

F350-6

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From: Texas

Welcome to FTE. Do you have the relay installed under the hood? There's a little box near the master cylinder that holds 2 sq relays. The relays need to be in there for the power to work at the rear plug.

May 7, 2008 | 08:42 AM

BillyBob69

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From: Wheatland, Mo

Remember that the 12v out at the plug does not work unless the ignition is on. Also what F350-6 said

May 7, 2008 | 08:45 AM

superduty4x4

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From: Newport, WA

Sometimes turning on the headlights will power the 12v at the trailer plug as well- that's what I had to do on my old 95 F250 if I needed to run interior lights in the trailer.

May 7, 2008 | 06:07 PM

racin87

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From: Humboldt,IL.

[quote=F350-6;6126054]Welcome to FTE. Do you have the relay installed under the hood? There's a little box near the master cylinder that holds 2 sq relays. The relays need to be in there for the power to work at the rear plug.[/quote
If this is the little box beside the fuse box no

What do you ask for if you go to NAPA?Thanx again!

May 7, 2008 | 06:42 PM

BillyBob69

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From: Wheatland, Mo

If you have your owners manual, you can look for it in there. It will give you the rating, and what they do. They are like fuse/relays. You can even get them at the dealer pretty cheap. I got mine for the backup, tail lights, power and brake including the brake controller pigtail for about $14.00

May 7, 2008 | 07:55 PM

F350-6

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From: Texas

I don't know about ratings on relays, but as BillyBob said they're pretty cheap. I'd bet if you take the truck down to Napa and tell them you need the relay for the truck they could get you one that will work. Just make sure the prongs will line up properly to plug in.