Can anyone tell me exactly where the “ground bus” is on my 97 Park Avenue? I have a myriad of electrical items not working (dome lights, trunk release button (but it works with the key fob!?), volt gauge, A/C, visor lights, etc.), and I suspect it could be this mysterious creature to blame. I read a nicely documented thread about this scenario with a different model GM car. But I tore the driver’s side apart, and found no such part.
I did have some luck about two months ago, when I hit an unmarked culvert replacement at cruising speed. The resulting WHUMP made all the devices “connect” again, and work perfectly. But, I thought I’d do a PM on the battery connections a few weeks later, and afterwards, the “Dukes of Hazard Fix” was no longer working. Any thoughts would be greatly appreciated. Thanks!

Many times there are various locations for a ground bolt that has several larger ground wires attached to it. Then within various harnesses there are ground splice locations that eventually go to one of the chassis grounding locations. It does sound like you have a loose ground or it could be a power wire. A place to start checking might be the battery and where it grounds to.

Remove the knee panel under the steering wheel and move some wires around. Check all fuses. Look for a bad connector on a wiring harness. ETC.....

just my 2 cents
BPA