Here’* a little story for you – I didn’t know whether to post it in electrical or general, so I’ll just post and let the mods determine the appropriate forum. Read on:

I pulled the radio out of the car last night (93 SSE) because I’m going to install one out of a newer Bonneville. That’* how I left the car last night, no radio no trim panel. My daughter decides she needs to drive mom’* car to school today so she goes and starts the car. Comes back a minute later and says the car’* making a funny clicking sound. Sure enough, turn the ignition on and the relay for the automatic headlights is clicking like a machine gun. So I’m thinking maybe the radio has to be installed for the electrical system to work properly – I’ve seen stranger things. It’* installed. Turn on the ignition and the relay still clicks and the display on the radio is deliriously whacked. So I turned off the automatic lights and the relay quits a-clickin’. Thinking maybe I hosed the relay somehow and maybe there’* a short and it’* causing problems, I figure I’d better try the headlight switch. Pull it out, the lights come on…and the radio antenna goes up! What the…? Turn lights off, antenna goes down, turn lights on, antenna goes up…I’m thinking I’m scwewed. I’m laughing my a$$ off and crying the blues at the same time. Ah, I think, maybe I’ve cornfused the ECM. So I yank the positive lead on the battery and let ‘er sit for an hour or so. After time goes by I install the battery lead and turn on the ignition. Lookin’ good. Enable the autolights and the relay still clicks. Operating the headlight switch with the autolights disabled produces same result as before – lights go on, antenna goes up. And I discover, as a bonus, you don’t even need to have the key in the ignition to do this. Once again I’m simultaneously laughing and soiling my britches knowing I’m in store for a nightmare of spark chasing.

At this point I decided I needed some wisdom from the gods at BC. So as I’m sitting here beginning to type my woes unto you, I think “You know, I didn’t connect the antenna to the radio.”. All other connections were made, but not the antenna. No way that could possibly affect the electrical system. No freakin’ way. But I decided to go ahead and plug the antenna into the back of the radio anyway. Stupid car is now working fine. Lights work, radio is no longer functified, antenna is under control. How…the heck…can the freakin’ ANTENNA coax POSSIBLY affect the light switch!? Ya got me.

Anyway, thanks for helping me solve my problem. I’m certain your collective brains felt a disturbance in the Force and subconsciously told me to connect my antenna. Even though the problem is solved, I thought I’d post my ordeal here for future reference. Maybe this is something already known, I was too lazy to do a search – not that I’d know what to search on!

Did I mention my car is white?

Ummmmmmmmmm, OK

By the way, unless they changed it, the antennae lead is a major ground point for the dash.

Sounds like a short some where. Have you checked the fuses? I've heard of blown fuses making other accessories go nutty because they somehow get partially grounded elsewhere then. Also, disconnect the antenna in the trunk. Do the lights still go whacky?

Now THAT would explain all my problems. The logic escapes me, why they'd use the antenna coax as a main chassis ground for the dash instead of a ground strap. I kind of suspected something like that when connecting the antenna solved my woes, but I thought "Nah, that'* ludicrous.".

I'm filing this little tidbit of information away for future reference: Car won't work right without radio. lol

Years ago I had a similar situation, except in reverse. I was installing an aftermarket receiver (well before "headunit") it would blow the taillight fuse, and then cause a popping sound in the speakers, whether or not the thing was turned on. Running a separate ground solved the problem. Guess it caused a ground loop, somehow.

Stan...lol

IIRC the 93 radio controls dimming to ECC and a couple other things. My first thought is something got pinched or rubbed and grounding you out.

Archon:
Where did you install the separate ground?

Boosty:
My first thought was "I'm screwed."
My second thought was "Maybe the radio has some component that controls lighting".
My third thought, after reinstalling the radio (sans antenna), was "I'm REALLY screwed".
My final thought, after reconnecting the system ground by inserting the antenna wire into the radio, was "I need to kill something. Anything."

I found a good ground on that particular vehicle over by the emergency brake release handle.

Cool. I'm going to go back in the lab right now and make a good ground wire, then go find a good place to connect it.