Wipers not working

I’m restoring a 1974 V8 manual. It’s been off the road a good while and I’m working through electrical problems. The wipers and motor don’t work at all. (It’s not a linkage problem). I started by checking the security of the switch connections, fuse etc which checked out ok. When I investigated further today, I noticed the ammeter didn’t indicate a power draw when the dash switch was operated. However when I swapped the motor for a spare (condition unknown) the wipers still didn’t work but the ammeter did indicate a draw. Is there anything I should check first, have I just got two duff motors?
without looking at wiring diagram and checking power feed (both sides of fuse) to motor etc not easy to guess at why. have w thought about jumping power directly to wiper motor(s) see if motors are stuck? failed? might be a simply broken connection etc I stripped down my entire wiper motor assembly .checked everything and rergerased /rebuilt. I has non working intermittent but food a hairline crack in black vacuum tube to motor assembly. bit of rubber hose and away it went!