Just finished installing the power only towing mirrors. I had to use the connectors off the old power mirrors. I pulled the female connectors out of the terminals off the old mirrors and the solder them on to the new mirrors and the stick them back into the terminal. I can tell you how the wires need to go with this exact setup.
05 with power paddel mirrors going to towing mirrors with power only. But I have a feeling it will be a case by case basis.
Depending on the manufacture of the mirror. If it is Ford that is easy. But there are others where the wiring colors do not match the truck.
I love my mirrors I cant believe the difference in the way the truck looks and how much better I can see.