1983 Cadillac DeVille - What is this part?

One the v-belt system the alternator does not turn. It is connected to the fan and the fan is supposed to be connected to the crank pulley but the belt is missing. Besides that, when I start the car and look under the hood the crank pulley is not moving, so the replacement belt would do no good anyway. Ive been on Google and been asking auto repair places for help but without bringing my car in, I cant get anyone to tell me what this part I need is and how to get one. I would like to do the job myself if i can get this figured out. The car works good besides this i want to get her on the road again.

Probably the harmonic balancer.

No clue. Your description doesn’t tell me anything. That leads me to believe you are unable to fix this even if you find out what the part is. Sorry, that is how it appears.

Whoa… Your problem description is a bit confusing. Are you saying that the crank is not moving but what I think you may be trying to describe is the loss of your harmonic damper? The harmonic damper is what the main pulley would bolt onto…on the crankshaft of the engine.

It sounds as though you are saying that the pulley or damper are missing? This is not a common thing to happen… How did this happen? Did the belt fall off during your last drive or use of vehicle?

Please describe how you have arrived at this point in time. What led up to this ? We like stories so give us as many details as you can.

Do not run the engine until you have it looked at, it could be damaged.

I do believe you are talking about the harmonic balancer as mentioned. Could be the key is sheared also. So tow it to a shop and let them figure it out. My Buick was about $500 for a new balancer installed.