Yes, I actually used a 1991 535i seat and put it in my 1990.
Your local BMW dealer will have the diagrams for the radio wiring of the 1990 535i. They carry that kind of information and will likely share it with you.
where the fuse located for power seat on 1992 BMW 535i
Check the fuel pump, fuel pump wiring, fuel pump relay and fuel pump fuse.
The fuel pump on my 1988 535i is right next to the back right tire. It is harnessed next to the fuel filter. I'm not sure if it would be there on your 7 series, but you could get under there with a flashlight and give it a look.
how do i locate fuel filter on 1994 BMW 520i
Maybe the fuel pump is going out or the fuel filter is clogged...
Sounds like your fuel pump is not working correctly. Check the relay and then work back.
I have a 1989 535i and the battery is under the back seat.
BMW 535i (E34) engine code 36 6S 1 3535cc is a straight 6 engine.
how u change fuel filter on 1998 BMW 740 il
It's under the passenger side air filter. Remove the filter and unscrew the relay cabin. It's a plug and play device.