This may help on a wiring diagram.
This picture from the Etrailer site shows the 7 wire plug color codes that Sunline used on the travel trailers, 5ths wheels and I suspect the truck campers.
Look at the image in the center
called "7-way RV standard"
that is the color codes Sunline used on the DOT lights.
Here is the whole article from Etrailer https://www.etrailer.com/faq-wiring.aspx
Scroll down as there is a lot of info there.
HEADS UP! The standard "trailer industry" often follows their standard on color codes which is not the same as the RV industry. And the E trailer picture showing a trailer wiring setup does not follow the same colors are the RV industry uses. The wires from the device to the location on the 7 wire cable pins on the back of the truck are the same, so a truck 7 wire receptacle will work with either a standard trailer industry or the RV industry wired trailer, but the color of the wire is different.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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