Can someone tell where the blue wire goes to the coil plus or minus?

Dave

What year car?

Plus.

The car is a 1971 240z built in March, I think it was on the plus .

Dave

I took that off my 71. I think all it was for was noise suppression. Car runs the same without it.

Yes, that is a condenser for reducing electric static on the AM radio stations, there should be one on the alternator also.

Bonzi Lon