Solar panel

[dfandrews]

Originally Posted by Daubsy

Im stumped. I used jumper wires to connect the controller directly to the pigtail, and it still didn't work. Voltage from the pigtail is reading 12.7 - 13.4v, so the controller should be powering on. Im using this controller.

It must be in the way that the 7-pin trailer cable is wired to the battery?

Sean,
Let me see if I can help, by saying it in my words:
First, here is a diagram that is very clear, and has both color schemes used for trailers (traditional, and RV).

Trailer Wiring Diagrams | etrailer.com

Scroll down until you find the 7 pin pics. Ignore the one on the right. traditional and RV only differ in some of the colors used; the pin outs are the same.
12V+ is on the top, off-center to one side, and ground is on the bottom on the other side, directly across the circle.

Pin 4 is black (12V+)
Pin 1 is white (Ground)

To verify the 12V+ pin, you can take the ground (black) probe on your meter and find a bare metal spot or bolt on your trailer frame to connect it to. If you find a spot or bolt for the ground probe, then poke around with the hot probe (red) in your plug until you get a 12V+ reading on a pin.
Now re-test with the red probe still on that pin, and the ground probe on the pin on the opposite bottom pin. That should give you the identity of your pins.

Or, you can test pairs of pins, working your way around the circle, and always with one probe 180° opposite the other probe.
Help this helps; remembering that electrical troubleshooting is a misnomer, it's really lots of fun.

[Ron in BC]

I admit it, I get a little lost reading write-ups. Here's a 7-pin photo showing meter hooked up to the 7-pin connector. Is this the same as your situation?

Don't laugh at my old Radio Shack Micronta. Had it for about 25 years. Still use it often. Little story about buying a warranty extension. Guy really wanted to sell me a warranty. It'll get replaced free if it fails he said. Since I was taking it to a boat overseas I said "if it fails it'll be swimming with the fishes" 25 years and still going strong.

Ron

[Daubsy]

Ron, from your picture it looks like the positive pin is correct for the battery charge (pin 4, black). However the ground pin is different. Mine is on pin 1 (white), directly across from the positive pin. I confirmed with meter readings that both the trailer 7-pin and controller harness follow the RV standard, and everything is wired correctly. So, there's really no reason why this shouldn't work. The only thing I can think of is that maybe the controller is very finicky and the voltage drop from the trailer wiring is enough so that it doesn't detect the battery. I will try to document with pictures soon.

[tractors1]

Originally Posted by Ron in BC

I admit it, I get a little lost reading write-ups. Here's a 7-pin photo showing meter hooked up to the 7-pin connector. Is this the same as your situation?

Don't laugh at my old Radio Shack Micronta. Had it for about 25 years. Still use it often. Little story about buying a warranty extension. Guy really wanted to sell me a warranty. It'll get replaced free if it fails he said. Since I was taking it to a boat overseas I said "if it fails it'll be swimming with the fishes" 25 years and still going strong.

Ron

Those are the two pins I jumper to turn on the trailer marker/running lights when working on my rear view camera ...........not power & ground.

[cpaharley2008]

Originally Posted by tractors1

Those are the two pins I jumper to turn on the trailer marker/running lights when working on my rear view camera ...........not power & ground.

Not on mine, it is the top 2 pins to activate the lights....

[tractors1]

About halfway down this page are great plug/receptacle pinout pics:

Trailer Wiring Diagrams | etrailer.com