Part Two - How to wire a 4-Flat Connector?

[Rob-a-Billy]

I am trying to splice in a 4-Flat connector for a trailer. I have the Model 99 connectors (single, dual, and triple) that match the wiring diagram in the resource section, but I am c-o-n-f-u-s-e-d. Any help would be appreciated.

[Thunderfoot]

Not sure on your question... But a flat 4 trailer connector has:
1 wire for Ground
1 wire for tail lights
1 wire for Right brake/turn
1 wire for Left brake/turn

So, if you look at this diagram http://www.fordification.com/images/sch ... odel99.jpg you will need to splice into it this way.

The wire for ground you will have to connect a wire to the chasse of the truck.
Tail Lights splice to 285 (Brown wire)
Right brake/tail splice to 282 (Green wire)
Left brake/tail splice to 283 (Yellow-black stipe wire)

[Rob-a-Billy]

Bless you. I will try it out today and let you know how it goes... stay tuned.

[kaptnkaos]

Hey Rob-a-Billy,

If I was gonna go through the trouble of wiring in a trailer plug, I'd install one of the combo units that has a 7 round RV plug and a four flat plug.
With that installed and a single adapter, you can hook up any type of trailer you want.
They look something like this...

The 7 blade style has the extra wires for back up lights, electric brakes, & aux power.
It's really worth the little extra work in the beginning, in case you ever want to or need to use an rv trailer.

KaptnKA S

[Redcap]

Hey Rob-a-Billy,

If was gonna go through the trouble of wiring in a trailer plug, I'd install one of the combo units that has a 7 round RV plug and a four flat plug.
With that installed and a single adapter, you can hook up any type of trailer you want.
They look something like this...

The 7 blade style has the extra wires for back up lights, electric brakes, & aux power.
It's really worth the little extra work in the beginning, in case you ever want to or need to use an rv trailer.

KaptnKA S

My truck has blade-7, round-7, round-4 and flat-4. Wish I would have known about that combo box when I was wiring it up!

[kaptnkaos]

Yeah Aaron...

I just tore out a bunch of old wiring on my '68 CS that the PO had done done sorta like yours.
I got one of the combo units and enough 7 wire RV cable to run directly to the stock 7 wire CS plug on the frame.
It just makes life a little bit easier...
I don't know if I'll ever pull an RV trailer, but most of the commercial trailers are all 7 blade hookups.
I have access to a nice tandem axel covered trailer that has the 7 blade hookup as well.
I wired my bump trailer with a standard 4 flat plug on it...
I'm considering revamping that... that doesn't give me any back up lights,
But, I'm not sure they are really necessary for the bump trailer.

KaptnKA S

[Redcap]

Yeah Aaron...

I just tore out a bunch of old wiring on my '68 CS that the PO had done done sorta like yours.
I got one of the combo units and enough 7 wire RV cable to run directly to the stock 7 wire CS plug on the frame.
It just makes life a little bit easier...
I don't know if I'll ever pull an RV trailer, but most of the commercial trailers are all 7 blade hookups.
I have access to a nice tandem axel covered trailer that has the 7 blade hookup as well.
I wired my bump trailer with a standard 4 flat plug on it...
I'm considering revamping that... that doesn't give me any back up lights,
But, I'm not sure they are really necessary for the bump trailer.

KaptnKA S

I wouldn't bother with backup lights for your bump trailer, just one more thing to go wrong.

Most of the stuff I pull takes the big truck round-7, but I'm looking at a triple axle tiltdeck car trailer that takes a blade-7, so I'm giving that thing some thought.