Electrical problem

[Mike1carol]

I have a 2020 f350 dually diesel. I have no power to the pin in the 7 pin plug that charges the battery in an rv. Not at the bumper or in the bed. Fuses are good. Dealer can't figure it out had in shop 4 times. Any insight or help would be greatly appreciated.  Thanks in advance. 

[danielj]

Relay? Can't believe the dealer technicians can't figure it out. Just use a power probe should be a easy task for a dealer technician. Trace the wire and all the points it goes. Ohm the wire with the fuse disconnected. Maybe it got pinched on assembly. I'm assuming they made sure there is power at the fuse. Is there a grounding issue? Ohm the ground. 

[4thTimer]

Was it working previously?  

[Mike1carol]

danielj dealer says when they command it the pin is hot . Also computer says circuit is working,  test light says otherwise. 

[Mike1carol]

4th timer only tried it for the 1st time about 4 months ago when I bought a 5th wheel 

[akirby]

I believe it’s only hot when it detects that a trailer is connected?

[danielj]

9 hours ago, Mike1carol said:

danielj dealer says when they command it the pin is hot . Also computer says circuit is working,  test light says otherwise. 

 

6 hours ago, akirby said:

I believe it’s only hot when it detects that a trailer is connected?

But he is saying when they "command it". Mike1carol I am assuming they are connecting a diagnostics tablet to your truck and manually telling the computer to energize the pin. Are you testing it yourself without connecting a trailer or telling the computer to energize the pin?

 

I am hoping that pin is always energized. I have several devices that I use a 7way plug to plug into the truck to power the devices. (fuel pumps/ sprayers/ etc.... handy and universal)

[akirby]

26 minutes ago, danielj said:

 

But he is saying when they "command it". Mike1carol I am assuming they are connecting a diagnostics tablet to your truck and manually telling the computer to energize the pin. Are you testing it yourself without connecting a trailer or telling the computer to energize the pin?

 

I am hoping that pin is always energized. I have several devices that I use a 7way plug to plug into the truck to power the devices. (fuel pumps/ sprayers/ etc.... handy and universal)

Yes, theoretically “commanding” it should work.  But 35 years in IT taught me that’s not always the case and it pays to double check.

 

I don’t think you want something like that energized without something plugged in.

[danielj]

2 hours ago, akirby said:

Yes, theoretically “commanding” it should work.  But 35 years in IT taught me that’s not always the case and it pays to double check.

 

I don’t think you want something like that energized without something plugged in.

no different then your 12v accessories plug on the dash that is always energized in use or not. Only draws power when something is plugged into it unless it is shorted to ground. You have bigger problems if it is shorted to ground anyways. 

 

Next week when my truck gets to the dealer I'm going to check it out. 

[akirby]

16 minutes ago, danielj said:

no different then your 12v accessories plug on the dash that is always energized in use or not. Only draws power when something is plugged into it unless it is shorted to ground. You have bigger problems if it is shorted to ground anyways. 

Huge difference because one is exposed to rain and weather.

[danielj]

16 minutes ago, akirby said:

Huge difference because one is exposed to rain and weather.

True. I have never had anything newer than a 2005. I know older stuff was always energized with truck on or off. Fused no relay. It should still be protected from the elements with the cap to cover the plug when not in use. Short of crossing a pond or water covered roadway. I wouldn't be concerned unless that is why Ford made a change to only run power to it when it detects a trailer. 

 

Overall this is very interesting to learn about my new truck. Gives me more stuff to check out on it before I even get it.