Diagnosing Dim Camper Tail Lights When Truck Headlights Are On

[gwinger]

So.....

I’ve been monkeying around with the system now for about two hours…

The first thing I should say is that the running lights and reverse lights do not work at all. They might be so dim that I can't tell weather they are on at all but I'd say the are now completely off.....I'll check it again at night because they could be so dim......

The first thing I did was attend to the 7 way connections at either end of the umbilical cord. I either spread the prongs out on some or I bent the prongs in so that maximum contact could occur. I put dielectric grease on every part of the connecting metal pieces…..

The next thing I did was to test the ground like you’ve all been telling me…

I attached one of my jumper cables firmly to the frame on the under side of the truck and attach the other end of the jumper cable to various spots on the camper (see photo)…… it made no difference at all.

All the truck lights work perfectly….
All the camper lights work perfectly, except the running lights and the reverse lights when the headlights are on……

I’m definitely intimidated by that multimeter…… that knob has about 75 different settings and the whole thing in general has about four different switches. I wouldn’t have the slightest idea what position to have any of those switches or that knob in. That has to be simplified.

Then there is the issue of the new house batteries…… I still don’t think they have anything to do with the problem, nevertheless, I checked to make sure that they were wired in series correctly. They are……

I have 12.6 V now on the house batteries. The voltage does not increase at all when starting the truck……..

Bottom line…. I still have no rear tail lights or reverse lights when the headlights are on……. Brake lights and directionals work fine.

Now I’m just sitting in the parking lot contemplating life itself….

What next?

Dielectric grease is an insulator. If the contacts have a bad connection, that grease can make it worse.
"Dielectric Grease Definition: Dielectric grease is a silicone-based grease used to protect electrical components from dirt, moisture, and corrosion. Non-Conductive Property: Dielectric grease is an insulator, which means it prevents the flow of electrical current."

 

[bigbAZ]

Dielectric grease is an insulator. If the contacts have a bad connection, that grease can make it worse.
"Dielectric Grease Definition: Dielectric grease is a silicone-based grease used to protect electrical components from dirt, moisture, and corrosion. Non-Conductive Property: Dielectric grease is an insulator, which means it prevents the flow of electrical current."

This has been discussed in detail many times. I am a firm believer in dielectric grease. It won't prevent the flow of electricity to parts that are in contact with each other, it only fills the voids around the metal to metal contact keeping out moisture and oxygen, and making for a long lasting connection. It protects the connection.

The only flow it stops is what would have been from electricity jumping across a void, which is arcing and undesirable in an electrical connection. In other words, if it is stopping the flow of electricity the termination is bad to begin with, not having enough solid contact area.

Some people smear it on the outside after the connection is made but it is intended to go on first, putting it on after does not allow it to get to all the voids.

There is a study where dielectric greases were used alongside conductive greases and the connections with dielectric grease fared better. Conductive greases contain small particles of metal which are not always compatible with the metals in a termination.

 

[CharlesinGA]

Confused! What do the house batteries have to do with brake lights, turn signals and head lights?

If the truck's output is working its easier to use power from the camper's battery that backfeeds to the 7 way umbilical to do the testing. OP needs to find the junction box where the 7 way umbilical joins the wiring going to the camper lights, and open it and look for loose connections, shorts, whatever.

Leave the truck completely out of the picture.

We do not know what kind of camper it is or how old it is. Its quite common for manufacturers to use a standard metal 4x4 electrical junction box (or less, mine has a tiny handy box with everything jammed in it), and only newer ones use a terminal strip with studs for making connections.

 

[TheBar]

If the truck's output is working its easier to use power from the camper's battery

In post 1 and 41 the OP says the camper batteries won't charge beyond 11.7 volts. Which would cause dim lights. So he would have to use the fully charged truck battery for the test.

But, you posted a picture of both a Bargman and a Pollak type plug. SPED1 posted pictures of both types. I don't believe a camper would have 2 plugs much less two different kinds.

 

[Sped1]

I see what you mean. Charles posted 2 types and the OP also did indicating he has both types and I’ve never seen that before. What I would say now is find a mobile tech to look at it. I tried my best to help him. I think I’m also probably done.

I posted two types because I have two types…… there’s a short 2 foot section coming directly from the Camper, there’s a plug joining that section to another 10 foot section which runs in the bed and plugs into the back of the truck….

I’m not making stuff up……

 

[Sped1]

I will say this, yesterday afternoon I solved the problem…..

And ironically, it was with one of the plugs….

With one of the plugs, I couldn’t figure out how to get into the internal guts of it, but when it was finally opened up, it revealed that there was rust in some of the connections…. it also revealed the two of the wires were hooked up to the wrong spots. Don’t ask me how my camper lights worked for the past seven years like that but……

Both the male and female parts of that plug were replaced and like magic everything worked perfectly…..

Here’s some photos of the corrosion on the connections…..


But what I really wanna say, thank you all…

I never in 1 million years thought I’d be able to go back-and-forth with a whole variety of people for 66 posts. That’s 66 post of people trying to help me, and that is a beautiful thing. I’m out here by myself, but stuff like this gives you faith in humanity because with you all trying to help me, I never really felt alone…..

So from the bottom of my heart, thank you so so much…..

Sped

 

[gwinger]

Glad you found it.
I doubt if that little bit of rust was causing the problem. Looking at the wires, the white wire (ground) was inserted too far into the connector. It was actually crimping part of the insulation which eventually caused a loose or poor ground connection, or even arcing, depending on how far in the insulation was.

 

[Rene T]

Glad you figured it out.