Ford F-150 Negative Battery Terminal Concern

Discussion in 'On the Road' started by K3WR, Sep 20, 2017.

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  1. K6LPM

    K6LPM Ham Member QRZ Page

    Excellent write up!
     
    WA7PRC likes this.
  2. K5BBC

    K5BBC Ham Member QRZ Page

    On the other hand, does one really want to screw around with a circuit that stops several thousand pounds from coming through the back window? Not me.
     
    KB4QAA likes this.
  3. KG5QBI

    KG5QBI Subscriber QRZ Page

    A lot of people never tow with their trucks, or only tow boat and other trailers with surge brakes. And I would have to install a fuse, pigtail, and electric brake controler into my truck before towing a trailer with electric brakes. There is also often a second sizeable circuit for charging the trailer house battery. That one is even less likely to get used unless you tow a RV. In my case, I could hook up after the fuse and before the empty factory socket for the key off isolation relay for always on power, or install the relay and connect after, and only have power with the vehicle on. The down side is that if a trailer were connected, it might still power the rig off the house battery or the runaway trailer battery.
     
  4. KA9JLM

    KA9JLM Ham Member QRZ Page

    Not many people that I know of use a F-150 as a real truck.

    I sure don't use mine with a trailer. You need a real truck for that.
     
    W5WTC likes this.
  5. W4ERR

    W4ERR Ham Member QRZ Page

    Good point, there's also a ground too in the same harness
     
  6. KB4QAA

    KB4QAA XML Subscriber QRZ Page

  7. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    I found that out personally when I installed the radio system in the FORD SUPERFLEX!!! It seems they have an external SENSE resistor in the lead between the negative battery terminal and ground. This controls the charge from the Alternator.
    The alternator stopped charging when I had the radio ground leg on the battery negative terminal.
    Once I removed it it started working again. I solved the problem by grounding the radio system to the vehicle chassis ground!!!
     
  8. K5BBC

    K5BBC Ham Member QRZ Page

    11,000 pound tow rating, but hey, what ever makes you feel good about your stuff.
     
  9. W5WTC

    W5WTC Premium Subscriber QRZ Page

    I would recommend doing as the service bulletin suggests. Least chance of ground loop conditions. Fuse both the + and – as close to the bat as possible. However….. there is a hot wire that runs to the 7 pin RV trailer plug. On most models it is hot all the time regardless of key position. Most are at least fused at 20 amps. With a F150 truck you most likely won’t be pulling a RV trailer that utilizes this circuit. Stay away from hacking into the blue brake line. A little stray RF and your trailer is skidding.
     
  10. W5WTC

    W5WTC Premium Subscriber QRZ Page

    11K tow rating... I would go broke. the first 6k used up on the empty trailer only leaving room for about 4 to 5 head cattle. 11K aint that much in the real world of working folks.
     
    KA9JLM likes this.

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