One station won't come in until I turn the car off

I have the 2008 Buick Lucerne that the shop wanted $970 to fix, but it’s been running FINE ever since I just paid the diagnostic fee. 500 miles later, and all is well, except this:

I just discovered that it has another odd idiosyncrasy. ONE of my favorite stations can not be heard as long as the car is running. All other stations come in normally. The one that won’t work is on a preset button, but it doesn’t seem to matter if I remove the preset or not. Adjusting the volume makes no difference. Now here’s the weird part. Yesterday I discovered that the station could be heard when I turned the car off in my driveway. Of course all stations worked then, until the door is opened, as usual. I think the program will make the radio work for about ten minutes.

Is there perhaps some setting that will allow an owner to “censor” a station? (Obviously some previous owner who didn’t like NPR?) I did not get an owner’s manual with it.

Try erasing all the presets for all the bands, clearing the radio’s memory, and then setting them up one by one again. And put the station in question at some other spot in the list of presets than it is now.

Still can’t hear that station? Bring a portable radio out to the car w/you and see if the same thing happens, you can hear it w/the engine off, but not w/the engine on. If so, there may be some kind of rf interference the running engine is making, which is masking that station. Could be something in the igniton system or a alternator.

Is the rear window tinted? Some window tint companies in the 2000’s were using metallic tint on the rear window that will interfere with the reception of the grid type antenna on the rear glass.

If you hear a click or pop from the speakers when switching on the rear window defogger this would suggest there is continuity between the defogger grid and the antenna because of the tint.

I’ve moved the errant preset around and even removed it. It was a new preset that I put in, not one of the previous owner’s favorites. I have not tried removing ALL of them, in fact I’m not sure how because with the station frequencies displayed on the screen, SOMETHING has to be displayed in each slot.

Have you tried turning the car around?
Many modern antennas tend to be unidirectional when they get to the fringes of the station’s transmission range.

Is the rear window tinted?
Yes, but that would not account for the fact that all other local stations come in, and 89.1 comes in when I turn off the key. 89.1 doesn't even have static when the car is running. I guess the short black big based antenna on the rear roof is for the Serius satellite system which is not in use. (I'm too cheap to pay, except for NPR.)
Have you tried turning the car around?
I certainly haven't driven it 500 miles in one direction. I guess that would make all my local stations a little staticy.

It seems your vehicle is generating enough RF noise at the frequency of concern that the radio is going quite. That kind of problem may be difficult to solve. I don’t know what find of antenna your vehicle uses, it may have a glass/etched type or standard whip. You could try plugging in a different antenna to see if that helps or just use a wire about 3 feet long. The problem could be inside the radio and if so replacing it should solve the issue. Try using a portable tuned to the station near the car while it is running to see if you can detect any signal coming from the car. If you can tune the radio slightly off frequency that may help you hear the interference easier if the car is generating the noise.

There is a tsb for the rear defogger causing radio interference due to microscopic cracks. I wonder if the antenna has the cracks too and is not pulling in the channels properly.

Increased RFI in the rear window could interfere with weaker radio signals. If the rear defogger as the insulation cracks, that might account for the loss of your local public radio station. Public radio often has a lower power to save money. Are there any oth stations operating at low power that you can’t get? I suppose this means you would need to scan the dial in another car then the Lucerne to verify if this is the case.

Just out of curiosity–AM or FM? I can see AM band having issues–AM broadcasts seem especially susceptible to EMI from a running car.

In MG’s third post he stated 89.1, so ‘it don’t look’ to be AM.

If this were the Washington Post, they’d be claiming a Republican blocking conspiracy. Around here its 91.1 but sometimes I have to go to 91.2 or 90.9 for reception. Just depends on where I am or what time it is but there are three or four NPR stations with different frequencies that come in better so might try different frequencies.

I’m tending to think though that there is a general radio reception problem caused by something. I suspect either cell tower interference, redirection of the signals at the stations, or something, I don’t know. But I can’t get a 50,000 watt station from Minneapolis anymore 50 miles away but I can get a station from Chicago and Detroit with the same or less power. And in South Dakota I get better reception in the middle of nowhere than in the metro area. I think it all started to change some years ago with the consolidation of the media so all the stations are owned by just a couple conglomerates. But it might be just leaks in my tin foil hat that makes me think that.

I put my hand on the back of the passenger side headrest as I backed up today. That’s when I discovered that this car is equipped with DVD players in each headrest. They are totally invisible from the driver’s seat, and I’ve never sat in the backseats or known anyone who did.

Upon reading just part of the Visualogic A-1285/6 owner’s manual, I think I have discovered the issue. This is a top of the line pair of DVD players that come installed in NEW headrests to match the car’s existing interior. It really is a nice car that someone before me loved. The DVD players originally came with earphones that use a frequency to transmit to each one. They can view separate DVDs, or the same one. I just spent half an hour watching a DVD with plug in earphones, while trying to figure it out.

I think Cougar nailed it when he said

It seems your vehicle is generating enough RF noise at the frequency of concern that the radio is going quiet.
When I have some time tomorrow, I’ll dig a little deeper. I suppose finding the DVD players’ fuse will solve the problem. No one rides in the back seat anyway. Right now I have to make Mrs Happy by mowing the lawn.

So you’ve never heard this station in this car while driving, right?

Right @texasas. Looked for it, even had a preset for it, but can’t hear it until I turn the key off. At that time I suspect the DVD players and the RF they apparently generate shut down even though they aren’t turned on. I need to read through the whole online owner’s manual for the DVD players to see if they offer a fix, like a change to a freq I don’t want to hear.

Anyway, I think I’m finally on the right track.

Here’s your owner’s manual. The stereo info starts at page 3-75.

Yup, there it is, right in the player’s owner’s manual, page 23. 89.1 is one of many frequencies it uses.

Power Consumption 12V DC (1 1-15V) /1.4A (Max 1.6A)
FM Stereo Transmitter 88.5MHz / 88.7MHz / 88.9MHz / 89.1MHz / 89.3MHz
89.5MHz / 89.7MHz / 89.9MHz

I’ll have to see if there is a way to change it. More reading required.

Sounds like there is a R/F harmonic being generated in the car that swamps 89.1 frequency… As GSJ suggested, try a portable radio tuned to that frequency and bring it near the car and see if it behaves the same way…Also check to see if the Sirius Radio is getting power…They usually transmit into the car radio on a frequency you select. If that frequency is 89.1, you have found the problem…

I was going to suggest that maybe you need to adjust where the cat’s whisker touches the crystal but that solution belongs to an earlier generation. I think Caddyman hit on the cause. If you find it, please let us know. I am really curious.

Oddly the portable radio I took to the car worked fine. It may have something to do with the DVD player being hardwired into the car’s system. I’m sure the glitch is because of the DVD player being set to 89.1. If the player was originally installed in an area where FM 89.1 radio can’t be received, they would have had no reason not to set it up that way. I have read the whole DVD manual. I don’t see anything about how to change the freq. I asked the question on the DVD maker’s site, but have no answer yet. I also have not found a way to be sure what model the DVD player is. I only found one manual online. It may be for a newer unit. The car is going on eight years old now.

@Triedaq, my cat gave me a very strange look when I tried to hold her up to the chandelier in the dining room. Not sure it helped… :wink: