Runningaford
Registered User
I know a lot of guys here run a trailers, and would have a trailer brake. I bought all the stuff for an aftermarket installation, but since then, through reading, found that many trucks came with a factory tow option....
I crawled under the rear end just now, and saw two connectors open, one with 4 prongs(female), another with 3 prongs(female). I also found the trailer brake 4-prong female plug under the radio, and at that point in the system, I've got 12 volt constant hot(+), ground(-), brake light signal, and a fourth which I'd presume goes back to the rear for brakes(I'll check the rearend connections tomorrow w/DMM).
In researching this for a while today, I read that you needed an additional 2 relays mounted on the side of the main power box under hood; which would connect to C105, and C149. I don't have the additional two relays.
In the reading I did, most said these additional two relays were needed, but one guy said that diesels(manual I presume) used relays within the main box? I've got two relays in the main box, but both aren't labeled as to what they supply.
I decided to ask, since the four prong female plug under the dash is energized, and working. Does this indicate I'm good to go, or perhaps with the two side relays gone, the P.O. bastardized something?
The thread where I was reading this is: http://www.ford-trucks.com/forums/1371503-factory-trailer-wiring.html
ifrythings
"Your truck is diesel isn't it? On the diesels the relays are in the under hood fuse box"
Thanks In Advance For Any Suggestions!
I crawled under the rear end just now, and saw two connectors open, one with 4 prongs(female), another with 3 prongs(female). I also found the trailer brake 4-prong female plug under the radio, and at that point in the system, I've got 12 volt constant hot(+), ground(-), brake light signal, and a fourth which I'd presume goes back to the rear for brakes(I'll check the rearend connections tomorrow w/DMM).
In researching this for a while today, I read that you needed an additional 2 relays mounted on the side of the main power box under hood; which would connect to C105, and C149. I don't have the additional two relays.
In the reading I did, most said these additional two relays were needed, but one guy said that diesels(manual I presume) used relays within the main box? I've got two relays in the main box, but both aren't labeled as to what they supply.
I decided to ask, since the four prong female plug under the dash is energized, and working. Does this indicate I'm good to go, or perhaps with the two side relays gone, the P.O. bastardized something?
The thread where I was reading this is: http://www.ford-trucks.com/forums/1371503-factory-trailer-wiring.html
ifrythings
"Your truck is diesel isn't it? On the diesels the relays are in the under hood fuse box"
Thanks In Advance For Any Suggestions!