This diagram you found is correct for the physical wiring but the colors are not correct for the RV industry world that Sunline used.
The RV industry (called RV Standard) and the Trailer industry (called Traditional) will both work plugged into your truck but the colors on the wires are different.
See here, this is from the Etrailer page down a little from where you found the diagram.
Here is the truck receptacle. Trailer Traditional, meaning the trailer industry on the left, RV Standard in the middle)
Here is the camper 7 wire plug
I really do not know why the 2 industries never got their act together and used the same color code but they didn't.
Here are the differences in case you do not see them right off.
Trailer world to RV world color changes on the same physical wire
- Purple to Yellow for reverse lights
- Yellow to Red for left turn and stop light
Also in your diagram, Red is shown as the battery charging wire and on campers, black is the battery charging wire on a RV as Red is used on the left turn and stop light.
Hope this helps
PS. A link to the Etrailer site with those diagram is here https://www.etrailer.com/faq-wiring.aspx?legacy=true
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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