house battery will not charge when truck running lights are on

[lmabey]

I'm trying to figure out the electrical issue on a 1997 Bigfoot truck camper, I have checked my 7 way plug on the truck at the rear end and in the bed, Both are wired correctly per the truck diagram below. The 7 way extension I have to plug into the camper reads like the trailer plug below when either end is plugged into the 7 way on the truck and the opposite end is read.

when I have the camper plugged into the Truck I'm getting 13.3=14.7 volts to the charging wire at my house batteries. ( I do experience a 0.1 volt drop from the truck to the charge wire. ) If I turn my running lights I get no voltage to the charging wire. I was also having a back feed issue when my running lights were on back through the Backup lights on my truck but not the camper that I know of. So I disconnected the backup wire on one end of the plug. The turn signal and running lights work correctly on the camper.

But I'm still searching for ideas on the charge-line issue. Thinking about switching the auxiliary and running lights wire on one end of the connecting plug and see if that changes anything. Or just gives me no voltage when the lights are off, and constant running lights.

any Ideas would be helpful

 

[Learjet]

how is the ground?

 

[lmabey]

the ground on the truck is fine, and I do not have any other light issues on the camper suggesting a grounding issue.

 

[GCroyle]

Couldn't hurt to rig a test wire additional ground and recheck. And if the 7 way on the trailer is from 1997 that's got some wear and tear. Also might as well look at 7 cable way to trailer connections.

I run a separate ground wire on my rig, that makes 3 grounds, 7 way, ball and my dedicated extra ground.

 

[TRAMPLINEMAN]

By truck camper, you’re referring to an in-bed camper, correct?

 

[Wayne M.]

All this is screaming a bad ground or hi resistance/ greenery on the power line.

 

[lmabey]

Yes, this is an in bed camper. I will run an additional ground to the tie downs and one temporarily to the truck and see if I that helps any.

 

[Road Dog]

If yours is the Fibreglass camper then you have ground wires everywhere. I don't know about your model year but (from the 2011 manual) newer campers don't use a backup light:
#ad


Also check your fuses. Is this a new problem? Have you tried a different truck? You can use a 12V battery and manually wire up the different [camper] circuits to see if it's a truck-camper interaction.

 

[BDaugherty]

Ground problem

 

[BIGNASTY]

When I had a travel Trailer pulled behind the Dodge I had a similar problem, the flat connector (trailer to Truck) was the culprit. I was out when it went to pieces so I stopped at a truck stop and picked up a connector & socket used on REAL TRUCKS once installed NO MORE PROBLEMS EVER!!! Have converted all trailers to this system, it may have been a bad connection from the factory but its been my experience that the RV accessories are generally a POS even the commercial grade stuff isn't what it used to be.

GOOD LUCK I HATE ELECTRICAL PROBLEMS

 

[lmabey]

OK we warmed up to freezing and I made some test leads and did some checking tonight but only on the camper with a freshly charged battery hauled out for the occasion. Both ground wires on the camper tie down bracket read 0000 when testing for continuity through the plug ground on the camper so the ground within the camper looked good. Everything checked out to be wired correctly matching up with the way the incoming feed would be of the truck plug connection.
Then after Dinner I figured I should be checking for back feed voltage on the Back Up light center pin.

with the Aux powered I had a back feed of .009 volts to BU lights(ground 0.006) charge 13.0
with the running lights also powered I read a back feed of 0.283 volts to BU lights
(ground 0.052 volts) charge 12.0

How much back feed voltage would it take to light the reverse lights on my pickup ? (incandesent)

Also appears I have some issues with voltage on the ground. will be looking in the panel next

Any Additional Thoughts? anyone

 

[PBJ2500CTD]

Your symptoms indicate a classic ground issue or indirect power to ground issue. Without a schematic it adds significantly to the challenge. Thinking the issues through as presented it sounds as though the backup lights are completing the circuit for the running lights.
One place to start is where one of the expected is not happening...backup lights illuminating when they should not be.
What happens to the running lights (clearance & tail lights), brake and turn signal lights, and the power wire voltage if you remove the backup light bulbs?
Have you opened the 7 way connectors and checked the wiring connectors for corrosion or water contamination? You can have one wire of the stranded group make connection and indicate a passed continuity check with an ohmmeter, yet not be able to handle the designed circuit current.

 

[DavidC]

You could get an 1156 bulb, solder some test leads to it and do testing. It will put a load on the circuit where a meter will not. As Bruce stated one strand of a wire touching will give you continuity but a test light will glow very dimly on same circuit showing a wire problem. The 1156 lamp is 27 watts with about 2.5 amps. Load test lamps are invaluable for testing.

 

[lmabey]

some great ideas guys, I'll do some checking on the plug in connections on the trailer. I do have a test light and some bulbs so I can make one that will put on more load,
Thanks

 

[lmabey]

Ok, to tie a bow on this one, it warmed up again so I got back out side. This time when I plugged the the camper in via the pigtail I had nothing anywhere, pinpointed the ground being the issue on the pig tail going between the truck and camper,opened both plug ends this time, found a disconnected ground and enough bent connections inside to cause the other problems. The solution is always easy once you find it, as always should have started with the simplest and worked up from there.

 

[Learjet]

good deal...thanks for letting us know

 

[TFucili]

Been there many times.