Why are you looking at the wiring on the combi switch? Unless you're replacing all the wiring, factory relays and all with an aftermarket setup, you only need to look at the engine bay connector wiring. I've got an early 74 260z and just wired up the honda motor, I believe the wire colors are the same. I won't be able to test it for a week or two because I'm still working on other wiring updates, but I'll report back when I do test it.
I recommend adding a SPST relay to the circuit and lubricating the wiper linkage before swapping the wiper motor. I have very little experience with the Z, most of my car work has been old BMWs and Volvos, but I did take a multi-meter to a number of locations on the car and the voltage drop is pretty significant all around. I probably would not have done the swap as my wiring plans evolved and instead started with adding a SPST relay. You can quickly add the relay and possibly solve your slow wiper issues(also lube the two main wiper posts!). If it doesn't solve your issue, the relay won't have harmed anything or taken much time to install. If you unwrap the wiring harness where the wiper motor wires meet the main wiring harness about two feet from the engine bay connector there will be a LR (blue/red) single 18ga(16ga?) which splits into three and feeds the reverse light switch on the trans + washer pump motor. This wire is hot when the key is in and switched to Acc or Run. Cut this at the joint and the single becomes the trigger (85), the triple (87) receives +12v from a fused wire to the battery (30), and 86 is ground to the chassis.
I found the new aftermarket honda motors don't use the wiring colors mentioned in all of the writeups, likely due to the generic vs OEM unit. Also, it's NOT a '91 honda wiper motor. '91 was the last year of one generation and the motor you want is from a '92 to '96 civic or '94 to '01 integra, part #76505-SR3-A01. I ordered a $40 generic unit off ebay and it came with the hardware needed and the shaft was notched like the OEM wiper so no grinding to it was needed. The wiper mount still needed grinding, approximately where my squiggly line is. The heat shrink colors match the generic wiper wiring colors and the connector pic is from zcardepot with a slight enhancement to the colors.
'74 early ----- Generic 92-96 civic
260z 94-91 integra wires
Black ------------ Black
Blue/Red ------ Red
Blue -------------- Green
Blue/Yellow -- Yellow
Yellow ----------- White
Blue/white ---- Not used
TL;DR - install a relay and lube wiper pivots first, easier, quicker, cheaper.