tow relay and fuse fo charging trailer while towing
06-12-2018, 07:18 PM
#1
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tow relay and fuse fo charging trailer while towing
Have 2015 F150 xlt eco boost. Need relay and fuse so trailer battery charges when traveling. Ford parts had no idea what I was talking about and have read I forum where several people talk of same issue. Can anyone tell me part number, size fuse and where they go? I read maybe # 9 and #21 but 21 has an A an B. Both look to be for fuse only. Does it matter and is it 30 amp? Where did you get since my ford co has no idea.
Last edited by johng11; 06-12-2018 at 07:26 PM.
06-12-2018, 07:28 PM
#2
Senior Member
I know, more reading!
click 2014 and older
or maybe http://www.justanswer.com/ford/9rf00...ge-camper.html
click 2014 and older
or maybe http://www.justanswer.com/ford/9rf00...ge-camper.html
Last edited by Bluewoo; 06-12-2018 at 07:35 PM.
06-13-2018, 10:05 AM
#4
From 2015 on there is no fuse or relay to install. Starting in 2015 the smart trailer program detects the trailer brakes and activates the 12V aux line however the wire is only 18 gauge (might be 16) so is not capable of charging the battery. Ford told me and my dealer it is only intended to maintain a charged battery and run low current things like the refrigerator control board and clock. If you want the truck to be able to charge the battery or run high current items such as a 12V refrigerator heating element you will need to run your own line from the truck battery to the trailer.
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08-28-2018, 10:26 AM
#5
Trying to figure it out!
This new 'smart' system is killin' me. My trailer is connected, named and I moved it (put truck in gear and pulled forward) but still no power to the 12v aux line that I can measure with a digital volt meter (set on 20v DC). Anybody have ideas other than running a decent sized wire or solar so my battery doesn't die on a 15 hour trip?
Last edited by Scott91370; 08-28-2018 at 11:39 AM.
09-10-2018, 12:42 AM
#6
Member
I remember reading a post where a fellow had the same problem. A trailer tech finally figured out what the problem was. First was the guy would get out of the truck, leave the door open while going back to measure the voltage. Found out the truck door needs to be closed. The second thing was that ( i'm going by memory here so this may be incorrect) the key fob needed to be in the truck. Ensure these two things and then see if you get your 12 volts.
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Scott91370 (09-10-2018)
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09-13-2018, 11:00 AM
#10
Trying to figure it out!
I'm going to quote it direct just for ease...
Originally Posted by Shooter2018
Special thanks to Mike from Cargo Trailer Sales , 801 w 8TH st. Lansdale Pa. He is the one who figured it out. I have bought 3 cargo trailers from these guys in the past 6 years, they are the BEST bar none!!!!!!!! I wish I could say that of the service from my Ford dealer, with a two week wait for help?
Well like I stated from the beginning , I could not get 12 volt out of my rear 7 pin trailer plug from my brand new 2018 Ford F150 Lariat with the 3.5 EB. This also stopped the use of a third party electric hitch jack that I loved dearly on my old F150 setup. I read the manual front ward and backward. I joined this GREAT F150 website, I did the main trailer set up multiple times, still I could not get the electric hitch to work, or power my dome light and break away battery on my brand new ATC Raven Trailer.
Yes I heard the relay click in after the trailer setup when I applied the breaks. But when I went to the rear plug nadda, nothing..... still no 12 v power ..... you want to know why???? are you ready ................ two things have to happen.... while the truck is running and you trailer is still hooked up......you CAN NOT leave your driver side door OPEN, or walk to the back of the truck with your keys in your pocket. The truck will beep twice to let you know you walked away with your keys. What it is also telling you is that it automatically shuts off your 12 volt power supply to the rear plug if the keys are not in the truck OR the door is left open.!!!!! either one alone will shut it off. With that..... dome light works, power to breakaway battery, and YES just unplug trailer plug insert electric hitch plug and my electric hitch jack WORKS..!!!!
I hope this helps guys...... I am super glad I found this out..
Well like I stated from the beginning , I could not get 12 volt out of my rear 7 pin trailer plug from my brand new 2018 Ford F150 Lariat with the 3.5 EB. This also stopped the use of a third party electric hitch jack that I loved dearly on my old F150 setup. I read the manual front ward and backward. I joined this GREAT F150 website, I did the main trailer set up multiple times, still I could not get the electric hitch to work, or power my dome light and break away battery on my brand new ATC Raven Trailer.
Yes I heard the relay click in after the trailer setup when I applied the breaks. But when I went to the rear plug nadda, nothing..... still no 12 v power ..... you want to know why???? are you ready ................ two things have to happen.... while the truck is running and you trailer is still hooked up......you CAN NOT leave your driver side door OPEN, or walk to the back of the truck with your keys in your pocket. The truck will beep twice to let you know you walked away with your keys. What it is also telling you is that it automatically shuts off your 12 volt power supply to the rear plug if the keys are not in the truck OR the door is left open.!!!!! either one alone will shut it off. With that..... dome light works, power to breakaway battery, and YES just unplug trailer plug insert electric hitch plug and my electric hitch jack WORKS..!!!!
I hope this helps guys...... I am super glad I found this out..
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Mach5 (09-13-2018)