Radio needs code every startup

[Gaarath378]

I have a 1987 325e (10/86) with a stock radio (from a 325i no info more than that) ive recently put in replacing the aftermarket unit previous owner installed. (it was ugly and had an aux cable for the original iphone, time to go), and like the title says the radio requires a code almost every time the car starts up - if i turn the car off and walk away, i can see the anti-theft light beeping, and if i start the car up shortly after it doesnt require the code, but more than say 5 minutes and it needs the code again. I cant find anybody else who has had this issue, could it be an internal battery that needs replacing, or an issue with the wiring to the radio? It does not remember any saved radio stations but other than these problems works perfectly fine. Thank you in advance!

[ghrays]

Check that memory power is connected via this pathway (see the ETM for your car):
Fuse 21
Rd/Gn wire to pin V of C302 (the accessory connector)
Rd/Gn wire to pin 2 of C215
Yellow wire from C215 to back of radio

[Gaarath378]

Massively appreciate the help, for anyone else in the future that skinny connector is C215 (behind the radio), that white one with the large blue wire coming out of it is C302 (under the kick panel, to the left of the pedal assembly). For whatever reason the previous owner had cut the Rd/Gn wire from c302 to c215 just a couple of inches from the connector, if i had to guess probably while installing previously mentioned aftermarket radio. Radio works great now, remembers saved radio stations and does not require code on startup anymore.