No fans or horn...ideas?

There is no simple answer when it comes to Pantera wiring. Only time in chasing down the problem.
If the fans and the horn have stopped working, the first thing I would check is the wiring harness that runs along the front nose section of your car. Everything runs through this harness for the front end stuff. Fans, Lights, etc. You'll find in this harness 6 to 8 wires. If you have the wiring diagram, follow the colors and check the grounds as well as the connection ends.
I would suspect maybe a ground problem.
It runs out of the drivers side and splits into 3 sections. One section runs the headlight motor, one runs the headlight on the drivers side and the driving lights. The continuing harness runs along the front of the car to the passengers side which connects to your other headlight, running lights and fans. Which is shown in this picture running along the air damm. There is also a power lead and a ground that comes out of the passenger side front wheel well, that should connect you your horns. Most of the time it seems you'll find your connections are dirty or bad if your fuses are intact.

...Cozs' advice is 'Dead-On' accurate! I will just add, that in My case one of the causes of ONE fan failing was a burned out coil (actuating) on one of the fan relays. They are the Two rectangular metal boxes mounted on the bulkhead right at the 'corner' of the radiator, on the passenger side; on a factory 'stock' Pantera, anyway. Also; the 'Temp Senders' may be 'Dead'. Other than that, even though a fuse may test good, it will NOT conduct if the copper contacts are corroded,(or are 'bent' into a weakened position), you might try some 'Electrical Contact' cleaner spray, here. Also I replaced ALL fuses with the newer 'Glass' style; BUT you must be sure you get the 'European' fuses with the 'Pointed' ends. They are difficult to locate. sometimes you can find them at 'Kragen' Auto Parts. Good-Luck with it!...

SOLVED! The wire on the backside of the fuse box had came off. Of course I found this after checking ALL other options. Of course the rule is if you have 20 different possabilities, the problem will be found on the 20th check.