I really want to know if this is going to fix the problem or if I should keep going to find a short? Thank you for your help!
No one out in Internet land could possibly answer your question. But what I can tell you is this is how working on electrical problems often play out. That is you look for something of interest and then you either repair it, or rule it out. Wash, rinse, repeat.
Besides. What if it's not the source of THIS problem. It sure could be the source of the next problem. So it needs to be cleaned.
I can also tell you from experience that if ONE connector is shows signs of water damage, then it's likely there are others. If this were my car, I would inspect every connector in the area that I could easily get to. Plus I would inspect the central junction box fuse panel in the driver's kick panel. Look for any signs of corrosion especially on the back of the CJB.
If the fuse still blows after doing a through visual inspection, then the next method is to disconnect the wiring harness at the ending devices and see if the short goes away. Then work back through the wiring harness paying attention to every connector that the RD/WH power line from fuse F2.21 passes through. Yes. Perhaps a large unit of work.
OBTW, the fact that fuse F2.21 is the fuse that is blowing is a huge clue. It will narrow down which connectors to target.
For a job such as this, a set of Ford wiring diagrams can be a big help. If interested in getting a copy for yourself I maybe able to help. PM if interested.
1999-2004 fuse panel schedule:
http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271