87 GN - How to get power to interior with no motor in car


I have my engine out of the car currently for a rebuild.

How do I get power to the interior of the car?

I need to roll up my driver side window.

The idiot mechanic who removed my engine forgot to roll the window up before he removed the motor.

I assume the main lead wire coming off the positive side of the battery needs to be connected to another wire coming off the main harness which comes out of the firewall. And of course, I need to ground the main grounding wire (coming out of the negative side of the battery) to the chassis.

I just did not want to do trial and error and really mess things up.

Thank you in advance for any help.