I need a radio code for a 1992 bmw 735i - 1992 BMW 7 Series

Wiring issues is what is sounds like. I also own a 1992 735i Mine was because of a bad ground wire. BMW built the locks to be able to "deadbolt" you can only emergency unlock (when you have no power to the doors, or dead battery) on the passenger side. Also make sure you have a new battery. Or a decent one. Bosch or Interstate.

You can check this website you find there fuse box diagram and description for BMW e32 (1991)
BMW 730 735i 735iL 750iL e32 1991 fuse box diagram CARKNOWLEDGE

You will have to pull the radio out of the dash far enough to get the serial number. The dealer can look up the code, given the radio serial number. If they want to charge you for this service, find a different dealer.

If you have the model number for the radio and your vehicle docs, Any BMW dealer should be able to get the code for you, as long as its a factory installed radio

It will depend on the radio MAKE and MODEL
Try asking here

www.ukbookshelf.co.uk

as they offer free advice+code for these older BMW radios

Check under the rear seat on the passenger side. The bottom cushion will come up if you push it in and then pull it up.

hold the m button with the radio on it will display the serial # of the radio. call a bmw dealer and tell them you need a radio code looked up. tell them the serial number and they'll give you the code

overloading the circuit. It's doing what it's supposed to do. Put the radio on another fuse to lighten the load.

If the radio displays code or wait, then you have to make sure the ignition stays on for 1 hour before trying to enter the code. It is also possible the dealer gave you the wrong code. BMW had 3 different makers of radios back then. Blaupunkt, Pioneer, and Alpine. Make sure they checked which maker of your radio was.