Today I just wired our f-350 for towing a 2006 Saturn Vue, more or less your problem or objective except you are towing a trailer while we will be towing the Vue with the f-350. We normally tow the Saturn Vue with our 2002 Holiday Rambler class A motorhome.
Our Saturn Vue was wired for towing with our 2002 Holiday Rambler by a local RV mechanic about a year ago.
Our f350 has the standard flat 4 wire (factory). I was nearly sure the f-350 flat 4-wire plug would work but I need to make sure otherwise I might have a real mess on my hands; see caution by Norm and Janet above.
To convince myself that the previous mechanic followed the normal conventions, I did the following.
1. Bought a 12-volt test light at Harbor Freight.
2. Bought an 8-foot wire line from another tool company with one end open (with 4 wires: white (ground), yellow (left signal/brake), blue (right signal
brake), brown (parking lights, the other end with the standard round 6 male plug. The color code is the current convention.
3. Inserted no. 2 (the round part) into the motorhome female receiver. Then, using the test light I systematically confirmed that the turning signal and parking lights worked using the test light as a proxy.
4. Then removed no. 2, and inserted the coiled wire system normally used in the towing of the Saturn Vue with the motorhome, and then repeated no. 3 step...this confirmed that the previous person who wired the Saturn Vue for towing followed the color code conventions.
5. Then using no. 2 with a male flat 4 pen at the loose end plugged into the f350, I inserted the other end (round connector) into the Saturn Vue female receiver on the bottom of the grill.
The checked left and right signals, brake, and park lights...they all worked fine, and thus I have piece of mind.
This process took about 30 minutes. HEMI