1981 240d questions

[Jason Beal]

I just got a 1981 240d/stick. It has a few issues, but runs pretty darn well. I had a few questions I hope you can help.

1) Are all locks supposed to open/close when I use the key in the drivers/passenger door on this model? Mine don't but I'm not sure if they are supposed to.

2) Went to crank her today to see if she would. She almost did, but pooped out on me. She started fine the other day @ 40 degrees, but today at 25 she wouldn't go. After three attempts I began to hear a clicking sound on drivers side next to fire wall. What could that be?

3) Where does a block heater hook up? (When I buy one)

Thanks for any help. I drove her an hour home no problem after sitting in this guys driveway for four months. It needs all the fluids/filters changed but it's too cold right now to be outside for a long time. I wish Spring would hurry up so I can get started on this thing. I'm thinking she needs some fresh fuel too.