Wiring issue?

1967 GTX, finishing up a restoration on it. Having an issue with the wiring. My windshield wiper motor is not working properly, it will turn on but not park or shut off correctly, I have to almost get the knob in half way between settings to shut off. It is a 915 variable motor that was restored. I am actually getting a shock sitting on the sill plate when I use the switch. All other wiring on the car works properly. I did have the battery negative grounded to the battery tray when I was putting the wiring in, but as mentioned everything seems fine, lights, fan blinkers etc. Battery negative now grounded to engine block and I noticed unless I run a jumper from the negative on the battery to the body of the car I get no power to the car anywhere. That doesn't seem right to me? I plugged a different 915 wiper motor in the bulk head and it works improperly like the one in the car, shock and all. Any help appreciated.

!967 would have had a ground braid connected to the pass side cylinder head that bolted to the firewall , did you install that , and make sure that paint was not affecting it working ?

the wiper switch is grounded by the dash, so you also need to check the dash grounds as well.
new paint etc. might isolate the dash from ground and prevent it from working properly.
I don't remember the park circuit and how it works, but I do know trying to test that swtich outside of the dash gives a nasty shock.

ok, that settles the shock from the switch as I have it just hanging down, I'll put it back in and check.

Mounted switch in dash, problem solved. Thanks all.

simple fixes for wiring snafus are the BEST fixes.