Power Problems

[88 Riviera]

I have an 88 Buick Riviera T-Type. I am having a problem with the electronics. My Instruments, Interior Lights & Auto headlight system keep cutting in & out. I have no power to my display screen & my radio is not working. Without the display screen I have no control over my climate or radio. Without the instrument cluster I cannot tell how fast i am going or anything else. All of the manual operated electrical functions (headlight switch, door locks, glove box, gas cover, trunk, etc all work fine. I have checked all the fuses & relays. Does any one have an idea? Thanks, Dale

 

[Syndicated]

you should get a wiring diagram and check ALL your grounds.
A lot of times in older vehicles these ground connections will corrode or come loose.