One other possibility is that someone has tried to "fix" a bad ECU here. I've seen a few of these 89-up cars with jumper wires added to force the fuel pump on. Basically it's to add a ground path to the fuel pump- when the ECU goes bad, it no longer supplies a ground to the pump. The net result is, the main pump runs ALL THE TIME when the key is on. This doesn't sound like much but it's enough to flood a car, and sure, it could do weird things like blow a fuse.
Normally the pump doesn't start until the engine is turning and the ECU is receiving pulses from the crank sensor.
You'll be able to tell if someone has "hacked" the wiring here- simply turn the key to ON and listen under the car- if the fuel pump's buzzing constantly, while the engine is NOT running, you should pursue this problem.
The fix is probably: replace the ECU, then cut the jumper wire that was added to the harness (probably right next to the connector for the ECU, in the right kick panel.) It's probably obvious what wire was tapped into- it won't look like neat factory wiring.
I'm not ruling out the other suggestions about the FPR- this is just an alternative path that's not-so-obvious.
Hope this helps!!
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Rob Bareiss, New London CT ::: '87 244DL/M47- 225K, 88 744GLE- 209K, 91 244 183K. Also responsible for the care and feeding of: 88 745GLE, 229K, 88 244GL, 146K, 87 244DL, 235K, 88 245DL, 236K