I took a tester and tested the 7 pin trailer connecter. All pins worked except for number 4 12 volt charger. Is there something wrong or do I need to do something to turn it on to test it? Like put it in gear or what? The truck was running in parked when I tested it. 2001 F250 5.4 RWD

Check the fuse panel under the hood. That is where the 12v originates and usually the manufacturer either does not hook up the wire, but it is there in the bundle, or they do not place a fuse in the holder or both.

Most trucks with tow package require a 20-30 amp fuse to be plugged in under the hood for the 12v to work. Check owners manual for location of the fuse.

My 2010 Ford F150 had a envelope in the glove box with a 12VDC FUSE and RELAY in it with no instructions. Turned out these were required to be installed in the main fuse panel on top of the radiator to provide TOW VOLTAGE when the ignition key was turned ON.

remdog*1 wrote:Most trucks with tow package require a 20-30 amp fuse to be plugged in under the hood for the 12v to work. Check owners manual for location of the fuse.I just checked. The fuse is in place and it is fine. It is not dedicated for number 4 pin. A/C clutch, power door locks and other things uses the same fuse.

Wrong fuse. Check for another one. One in question is for charge only, I think the one you found is for the brake controller or the ignition control to energize the relay.

7 pin trailer connector - no 12 volt for charging

The_Texan
Explorer
Apr 26, 2015
Check the fuse panel under the hood. That is where the 12v originates and usually the manufacturer either does not hook up the wire, but it is there in the bundle, or they do not place a fuse in the holder or both.
remdog_1
Explorer
Apr 26, 2015
Most trucks with tow package require a 20-30 amp fuse to be plugged in under the hood for the 12v to work. Check owners manual for location of the fuse.
RoyB
Explorer II
Apr 27, 2015
My 2010 Ford F150 had a envelope in the glove box with a 12VDC FUSE and RELAY in it with no instructions. Turned out these were required to be installed in the main fuse panel on top of the radiator to provide TOW VOLTAGE when the ignition key was turned ON.
ugh
Explorer
Apr 27, 2015
remdog*1 wrote:
Most trucks with tow package require a 20-30 amp fuse to be plugged in under the hood for the 12v to work. Check owners manual for location of the fuse.

I just checked. The fuse is in place and it is fine. It is not dedicated for number 4 pin. A/C clutch, power door locks and other things uses the same fuse.
enblethen
Nomad
Apr 27, 2015
Wrong fuse. Check for another one. One in question is for charge only, I think the one you found is for the brake controller or the ignition control to energize the relay.
ugh
Explorer
Apr 27, 2015
RoyB wrote:
My 2010 Ford F150 had a envelope in the glove box with a 12VDC FUSE and RELAY in it with no instructions. Turned out these were required to be installed in the main fuse panel on top of the radiator to provide TOW VOLTAGE when the ignition key was turned ON.

That's it. The two relay was not installed. I found them in the glove compartment (hard to believe it was in there after 15 years) I just installed it, but it requires two additional fuses. I need to go buy the fuses tomorrow and test it.
ugh
Explorer
Apr 27, 2015
enblethen wrote:
Wrong fuse. Check for another one. One in question is for charge only, I think the one you found is for the brake controller or the ignition control to energize the relay.

You are correct. I need to buy two more fuses.
remdog_1
Explorer
Apr 27, 2015
That's it, just install fuse and check with tester. When you test it the key has to be on.:)
MitchF150
Explorer III
Apr 27, 2015
oops.. Missed that you had the truck running.. Never mind.. :)

Mitch
Blue_Hill
Explorer
Apr 27, 2015
I had the same issue. I connected the wire and installed the fuse, but now the terminal is hot all the time, regardless of whether or not the key is on.