Several things to check: 1) Is there power in the circuit? Check the fuse to insure that the circuit is energized. 2) Using a mutilmater of a troubleshooting light check of power is getting to the horn itself. First remove the wire to the horn, insert the the lead and then connect to ground. Have some one push on the horn. If power is noted there, the horn is either faulty or otgrounded properly. 3) If not pwer is noted, check the horn relay. This is where the problem usually is found.
The odometer on a 96 Ford Explorer is tied into the speedometer. If the speedometer is working then there is a gear problem inside of the speedometer causing the odometer to not work.
The fan motor has a short...change it.
You can use either or both ping/tracert.
I would look for a bad ground if the fuse is good
Identifying the problem you're having with it would be a good start.
99%, the problem is with the blend door in the Plenum box. This is a common fail on the Explorer and is the first suspect when you see control problems. Follow my user name to my Bio Page for pointers to the HeaterTreater web site. There is a lot of diagnostic information and a bullet proof fix for the problem on the site. ford4me
From a contributor's standpoint, there is nothing in your question that gives any kind of clue to troubleshoot the problem. It would help if you described the problem with some kind of detail.
Switch, circuit, shift motor
To Troubleshoot simply means to diagnose the cause of a malfunction. an example would be if your taillights weren't working. using a volt meter or test light you could test to see if the fuse had blown, you had an open wire, or both tail light bulbs were bad.
A cassette player can be fixed that stops taking tapes. It would have to be taken apart to troubleshoot the problem, however,
my control cable frayed....
Possible gear position sensor problem. Diag should reveal this.