AVIC 6000NEX lighting issue

[ligito]

I have a newly installed AVIC-6000NEX.

The installer used T-Tap connectors.

It is causing problems with my trailer lighting.

 

When I turn the unit on, the head unit lighting is normal.

When I pull the light switch on, the head unit dims, whether the vehicle is running, or not.

 

This is also making my tail lights on my trailers intermittent.

Sometimes the lights will work and sometimes, not.

Brake and turn signals are working OK, just an issue with the tail lights, on 2 different trailers that have been in service and work on other trucks.

[ptkdude]

I think the activity you're seeing on the AVIC is normal.  When you turn the car's lights on, the illumination on the AVIC should dim irrespective of the engine run status.  

 

As for the trailer lights, I don't see how installing the AVIC would affect that unless when running the wires the installer accidentally tugged on the trailer connector wires and as a result you have a periodic open in the circuit.  It could also just be coincidental that you started having a problem with the wiring to the trailer at the same time.  Since you're seeing it on 2 different trailers, and those trailers are working fine when connected to other vehicles, that's pointing to an issue with the wiring to the trailer connector on your truck.  Is there maybe some corrosion in the wiring or connectors?

[ligito]

In tried to install my new harness and socket but the harness was too short.

Now I have to order another one that fits.

[nismorg]

The head unit dimming is normal when the orange/white wire is used.  You an adjust the day/night settings.

 

The trailer light flickering.  make sure nothing else was damaged during the install. Do you have a backup camera?  make sure the trailer lights weren't sourced as power for the backup camera rather then a sig lighter.

[ligito]

The installer said he tapped into the backup light, behind the right rear lens, for the backup camera connection.

[jhren]

The installer said he tapped into the backup light, behind the right rear lens, for the backup camera connection.

And trailer light connections typically tap into those same conductors.  Appears you have a tap (or so) that is a bad connection.

[ligito]

I  installed the new trailer harness and it still work erratically.

I have low voltage at the fuse for the trailer running lights.

I have a new headlight switch and will try that before signing my life over to Ford, to find the problem.

 

The circuit is Headlight switch to relay, with a branch to the trailer brake controller, then on to the fuse and trailer harness.

 

I made a tester that includes incandescent lights for the trailer running lights and LED's, for the stop/turn lights.

I made a mount and glued it on the bottom, to attach to a tripod.

I set the tripod off to the side. so I can see when the lights are working.

 

When they work, the running lights are barely visible.

Then, when they feel like it, they come on full voltage.

I've not been able to determine the source of the proble.

[jhren]

Kind of hard to clue you in on best troubleshooting techniques.  Given this limited interface, I suggest you draw out a wiring diagram... every wire, every connection, every piece of equipment.  Measure voltage at each accessible point, referenced to a known good ground connection, both when the respective light should be off and when it should be on... and try to get measurements when it should be full on and when it is not full on brightness.  You may need to enlist an accomplice for this task.

 

If you have access to a multi-channel recorder that'd be real handy.  FWIW, there's some real good and inexpensive USB interfaces nowadays... but don't have any recommendations as I've yet to purchase one... no need at present.  The diagram annotated with measurements and when you took them will help you track down the problem(s).  I've been in plenty similar situations and wish I did what I suggest because I'd take the measurements and not write them down... ended up forgetting the value, when I took the measurement, or get one confused with another.