got a truck recently and the wires were hacked to the fuse box. the truck is a 2000 f550 XL interior with an automatic trans. T parted out a 99 f350 4x4 zf6 speed and am considering using the 99 harnes to replace the f550 harness. is the design of the harness the same for these models? I've pulled quite a few dashes apart from the 96 & 97 psd's and it sure seems like Ford uses a broad approach for wiring harnesses and steering columns

 

The dash harness should be the same between the two trucks you mention.

 

just pulled the dash on the 99 6 peed and it seems as the only difference so far that I noticed would be the wires for the clutch switch aren't use on the a/t since the neutral switch is on the side of the trans