Static in radio on Am

SIERRA2005 · September 19, 2005

Anyone have any suggestions on eliminating window motor noise, and engine noise On GM XM radio, Bose speaker system. . I noted going by power lines that the noise is getting worse. I thought it was the older transformers. Now I notice it when I use the electric windows.

Sierra 2005, Crew cab, 10,000 mile. I hate to take back for warranty, if there something I can check. Any help will be appreciated. Sierra05. Thank you in advance

Frozen001 · September 20, 2005

The problem is in the +12v going to the radio, it is not isolated from the noise enough. I would take it back and complain, but that will not say they will fix it. What should be done is an inline filter needs to be placed on the +12v supply. It could also be a bad ground somewhere... maybe the antenna connection is not seated properly. The real problem is that most people do not really listen to AM anymore, so the quality of the radios on the AM band have dropped, in favor of the FM and increasing popularity of XM.

Bill55AZ · September 20, 2005

AM stands for Amplitude Modulated, and is subject to interference from almost any electrical source. In the old days, there would be a "condensor" from +12 Volts to ground that would shunt the non-DC voltage to ground. Modern term for condensor is capacitor, and those can be bought at almost any auto parts store nowadays. You don't need one of the big ones. Capacitors are designed to pass low level AC voltages to ground, not high level. Most are electrolytic and they are polarity sensitive. MAKE NOTE OF THAT !!!! Make sure the + goes to the +.

And NEVER put high AC volts on an electrolytic capacitor, unless it is your intent to cause the capacitor to explode in your face.

The dealership should be able to measure the AC component that is most likely riding on the DC volts, and then add a condensor, or a filter, to eliminate the noise.

FM is frequency modulated, more complicated design inside the radio, but almost completely unaffected by electrical interference.

Frozen001 · September 21, 2005

Bill is correct, but this really should not be there on a new truck... I am sorry, but something is wrong....

mmmikkke · September 21, 2005

I've seen this happen when the antenna gets partially unplugged. There's still enough fm signal to work pretty much normally, but the am signal is severely attenuated and the agc (automatic gain control) in the radio amplifies the severely weakend am signal and you hear both the weak am signal and the electrical interference. Remove the radio yourself and see if the antenna is partially unplugged.

Black Bart · September 22, 2005

I tend to go along with Frozen and Miike, having been an auto radio tech eons

ago I have seen this problem caused by an antenna connector not making

good contact and also from water seeping down into the cable from the antenna

rod.

Try pluging in another antenna and see what happens.

SIERRA2005 · September 22, 2005

I thank all who responded. Thanks for taking the time.

I called dealer. The service Mgg's, First statement was "You listen to AM?" I said yes how else do you find out what Rush Limbaugh says. He did not know who he was, so it went down hill from there.

Final solution. Two days maybe? It includes fixing a squeek in the left front wheel area. When you stand on the running bar and move it squeeks. I should not have told him that? He said it is in the bar? I also told him the Air Conditioner did not produce as cold as air that my daughters Z71 does....

Does anyone else notice the Twilight zone theme song playing in the back ground?

I probably will never see my truck again.

mmmikkke · September 23, 2005

...how else do you find out what Rush Limbaugh says.

...I probably will never see my truck again.

<{POST_SNAPBACK}>

Hey, Rush is the reason I deep-sixed my factory radio. I listen to Rush too. And I couldn't stand how much worse the AM audio was on the GM radio relative to the AM reception on the Pioneer unit I had in the truck I had traded in.

So out came the Delco junk and in went a new Pioneer. Yeah, I said junk! I'm sure of it!

The Delco AM radio implements some sort of muffling circuit that replaces the static (due to its poor quality tuner) with a total cut of mid and high frequency audio. So as you drive in and out of marginal reception conditions (and for *this* radio, it's pretty often), it's like somebody keeps putting a pillow in front of the speakers over and over. It's more than annoying. It's embarassing! It's muffled. Now it's clear. Now it's muffled. Now it's clear. Now its muffled. It changes about that often. And it's that rediculous.

I was ashamed at such a display of engineering incompetence. It *had* to go.

Now that the evil radio has been exorcised, all is good. Rush is crystal clear. And the monument to cheezy engineering is outta my truck!

SIERRA2005 · September 26, 2005

...how else do you find out what Rush Limbaugh says.

...I probably will never see my truck again.

<{POST_SNAPBACK}>

Hey, Rush is the reason I deep-sixed my factory radio. I listen to Rush too. And I couldn't stand how much worse the AM audio was on the GM radio relative to the AM reception on the Pioneer unit I had in the truck I had traded in.

So out came the Delco junk and in went a new Pioneer. Yeah, I said junk! I'm sure of it!

The Delco AM radio implements some sort of muffling circuit that replaces the static (due to its poor quality tuner) with a total cut of mid and high frequency audio. So as you drive in and out of marginal reception conditions (and for *this* radio, it's pretty often), it's like somebody keeps putting a pillow in front of the speakers over and over. It's more than annoying. It's embarassing! It's muffled. Now it's clear. Now it's muffled. Now it's clear. Now its muffled. It changes about that often. And it's that rediculous.

I was ashamed at such a display of engineering incompetence. It *had* to go.

Now that the evil radio has been exorcised, all is good. Rush is crystal clear. And the monument to cheezy engineering is outta my truck!

<{POST_SNAPBACK}>

SIERRA2005 · September 26, 2005

Great tip. I too had a pioneer in my CJ7. Reception was rated one of the best. Trouble is I injoy XM other times. You cannot get it in a After Market replacement. At least not that I know of.

On different note you may want ot check out Michael Savage on XM

mmmikkke · September 26, 2005

Great tip. I too had a pioneer in my CJ7. Reception was rated one of the best. Trouble is I injoy XM other times. You cannot get it in a After Market replacement. At least not that I know of.

On different note you may want ot check out Michael Savage on XM

<{POST_SNAPBACK}>

Pioneer XM tuners can be had for cheap on ebay, they come with a 20 ft cable that just plugs-in to the back of the head unit. All the logic's already there. I got mine for $15 plus $10 shipping! Included the standard Terk antenna and all the cables! Took about an hour to install. Works great, sounds great. The head unit notices the XM tuner and gives itself another source. So you cycle through the sources you have with the source button: CD, Tuner, XM, Aux. and then it loops. 18 XM presets, 3 bands of presets, station display. Pretty standard for all aftermarket brands.