Loud Buzzing on AM Radio (2001 DeVille)

Oct 28, 2003 11 Replies

For awhile, this was intermittent, but now it's permanent. AM only, worse at lower end of band. I would guess it's most likely due to RF emitted by the engine's electrical system. My question: Will this turn out to be a separate module that needs replacing, or the whole radio? The AM signal is barely audible so I know the tuner is working, it's just being drowned out by the "static." I'm praying the filter is separate- changing the radio is a mess! Thanks for your help! Frank


Please check the antenna lead in cable, if disconnected you will not receive a AM signal.

I once had a 1985 Chevrolet Celebrity Eurosport that I had to reroute the antenna lead-in cable due to opening the glove box pulled the cable out of the rear of the radio.

If that is not the problem, you may have a open circuit either in the lead-in cable or antenna.

Thanks for your reply! I can hear the AM signal in the background as I said. Something may be disconnected, though. Earlier, the signal would suddenly get buzzier. I could stop it by switching the directional signal up and down. I reasoned that anything that created a spark would cause the connection to restore temporarily, at least insofar as RF transmission was concerned.. This solution doesn't work anymore, however. Does this in any way help with the diagnosis? Frank

Sounds like the antenna lead came out of one of it's sockets. Check them all and reseat them all.

Dear Frank:

Switching the directional signal up and down does not really tell one much. Your radio only receives RF transmissions. The sparking or arcing noise is commingled with the RF signal.

One manner of trouble shooting would be plugging into the radio a inexpensive antenna like from Radio Shack.

snip

The devilles antenna is built into the glass, right? and a good chance that it is active with electronics (front and back window) to get the best performance for FM. If this is the case then it is most likely that the electronic module has lost a good ground. They are good systems, but the long term issue is a good ground on these modules.

Yes, and it sounds like you may be on the right track, but remember the FM is fine, this is an AM *only* problem. Does AM have a separate spark suppressor? Also, remember I said I can hear the AM signal in the background, it's just mostly drowned out by the engine RF. P.S. Thanks to all who replied!!

AM is a lot more sensitive than FM. FM modulation will filter out the noise... Also check for a bad battery or alternator....

Today the problem became intermittent again. When it would start to recur a simple snapping on off of the directional signals (or anything else that would cause a small arc) would cure it for awhile, just as I had reported previously. I won't take the car in until the problem becomes permanent, even though the car is still under warranty (Cadillac certified) because I think it would be too difficult to diagnose at this point. Intermittent problems always are.

Don't know why you wouldn't take it in. They could have service bulletins that cover the problem or just replace the radio. If it is under warranty take it in...

JUST THOUGHT I WOULD SUGGEST THAT YOU MAKE SURE YOU HAVE A GOOD BATTERY GROUND ....SEEMS TO BE BEST FIX ON BUICK Hope this helps steve

As long as its under warranty bring it in. Even if they hear a pop or crackle on the AM band they'll probably replace the radio Nobody repairs anything nowadays Everything is throw away.

When I was at Chevy last week a new AM-FM Cassette radio for an 02 Tahoe was sitting on the parts dept counter. The work order ticket indicated " No Sound " when tape inserted. So they just put another rardio in & hope it works. Sticker on the radio said Made & Assembled in Mexico. The radio was so light there was nothing to it.

An 02 Impala came in last year with bad radio reception - the fix - replace the rear window ( built in antenna ) .

Good luck.

========= Harryface =========

1991 Pontiac Bonneville LE ~_~_~270,000 miles_~_~_

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