I wouldn't be able to say what pages because I printed it offline. All I have for a reference is section 22-42. It talks about the relay pins being different colors
I checked section 22 of the 1991 manual. There are no references to black/white wires associated with the blower controls; but, I have to admit that the scanned .pdf version of section 22 is not the best quality and some of the wire color codes are difficult / impossible to read on the diagram. The wiring diagram at the end of section 23 (electrical) is much better.
There are two relays associated with the blower motor. The BLOWER RELAY and the BLOWER HIGH RELAY. On page 22-42 of the manual, it describes a test where you remove the BLOWER HIGH RELAY from the relay box and then run a jumper from the black/blue female terminal on the BLOWER HIGH RELAY plug to ground. With this jumper in place, turning the ignition key to on will force the blower to run on high speed even if the climate control unit is completely dead. It sounds like you had the key in the on position before you applied the jumper so, even if the blower motor works, getting a small spark when you connected the jumper would be normal. If you got a large spark, that sounds like there is a short in the blower motor or across its connector which would definitely blow fuse #28
If you did this test on the BLOWER RELAY instead of the BLOWER HIGH RELAY and you jumpered the blue/white wire to ground then you will definitely blow the #28 fuse; but, should not damage anything other than your ego.
Your blower motor may be on its last legs and shorting out internally. However, @Jinks
may have the clue. If the two wire plug that connects to blower motor is open circuit that will result in non operation. However, based on what you described, if its shorted internally that will cause non operation and the #28 fuse to blow. Carefully examine the plug terminals on both the blower end and the body side wire harness end (a major pain to get in there and check the body side plug). Look for broken wires or insulation or internal shorting on the plug terminals. This may require pulling back the protective covering on the wires to get a good look.
If you don't find any damage to the plug, install your new blower motor; but, don't power up normally. I suggest you repeat the Blower High Relay test on page 22-42; but, remove the #33
fuses that supply the climate control unit. With the blower connected up, remove the Blower High Relay, jumper from the black/blue wire on the blower high relay socket to ground and then turn the ignition key to run. If the blower and associated wiring is OK, the blower should run on high speed. If the blower does not run, check fuse #28
. If it is blown then you have a short circuit in the wiring someplace. If the fuse is not blown, then there is an open circuit.
The reason I suggest removing the #33
fuses that power the CCU is that I don't want the CCU powering up and trying to run the blower at reduced speed by modulating the power transistor. If there is a dead short across the blower motor a full 12 volts gets applied across the power transistor. If this happens and the CCU is switching the transistor with a short pulse width, the I2T melting time on the fuse may be longer than the overcurrent damage time on the transistor resulting in damage to the transistor. If the blower successfully runs on high, then turn everything off, remove the jumper and reinstall the blower high relay and the fuses for the CCU and then power up normally.
If you find that the CCU powers up; but, that the blower only works on the high speed setting, the blower power transistor may have been damaged.
To find the fuses, Honda used to provide fuse 'maps' on the top and sometimes on the inside of the relay / fuse box covers. If those fuse map don't exist on the fuse box covers, then check your owner's manual and you should find the fuse 'maps' there. If that does not work, then go to page 23-47 of the electrical section and they provide a numbered map for the fuses. All the fuses are in the big main relay box up front. Note that the #28 blower fuse is one of the large screw in style fuses.