Rear defroster issue?

[malibill]

Hi everybody, Bill here not sure if I am in the correct forum hopefully I am anyway I have a 2003 Marauder totally stock that I am having a problem with the rear defroster.. With the radio on I hit the button on the dash for the rear defroster and it "mutes the radio" the station light is still on but no sound from the radio??.. I have had this problem since I purchased the car a few months back but only realized it when I went to use the defroster.. Thanks to Fadstblackmerc I have installed one of his upgraded bcm that repaired the issue with the fan works perfect now no more up and down speeds from the blower.. Anybody have any thoughts or ideas please let me know Thanks in advance and Thanks again to Fastblackmerc great job and price on bcm...,highly recommended:beer:..

[RF Overlord]

That's not uncommon. Check all the grid lines for any that may be cracked or broken. This will cause arcing that will wipe out the radio since the antenna is part of the grid. May be easier to tell if you put the radio on AM as the arcing will produce a very distinctive hissing or buzzing noise.

[malibill]

That's not uncommon. Check all the grid lines for any that may be cracked or broken. This will cause arcing that will wipe out the radio since the antenna is part of the grid. May be easier to tell if you put the radio on AM as the arcing will produce a very distinctive hissing or buzzing noise.
Thanks , going to give it a look hot as blazers here right now (L.I.,N.Y.) might wait till tonight as it cools off a little?/ Is their a repair? That back seat would be really hot lol?? I will give an update as soon as I check it out.. Bill

[malibill]

Thanks , going to give it a look hot as blazers here right now (L.I.,N.Y.) might wait till tonight as it cools off a little?/ Is their a repair? That back seat would be really hot lol?? I will give an update as soon as I check it out.. Bill
Well just took a quick look the connections on both sides seem good theu are not loose or corroded didn`t notice any cracks in defroster lines but no sound on am station?? I forgot to mention it is the stock factory radio 6 cd changer in trunk cds work good and so does the fm radio?/ But I am guessing from your tip I might have a bad radio??

[fastblackmerc]

Well just took a quick look the connections on both sides seem good theu are not loose or corroded didn`t notice any cracks in defroster lines but no sound on am station?? I forgot to mention it is the stock factory radio 6 cd changer in trunk cds work good and so does the fm radio?/ But I am guessing from your tip I might have a bad radio??

Unlikely that the AM portion of the radio is bad. Usually the FM goes away. You'll need to check the lines very closely.

[malibill]

Unlikely that the AM portion of the radio is bad. Usually the FM goes away. You'll need to check the lines very closely.
ok , is their a repair for this?

[fastblackmerc]

ok , is their a repair for this?

For the lines, yes there are kits. Most FLAPS will have them.

[RF Overlord]

I ass-umed from your first post when you said turning on the defroster "mutes the radio" that you were talking about the FM side. So you're saying the FM works fine, and it's the AM that mutes?

[malibill]

No with the radio set to fm it plays fine when you hit the rear defroster button no sound but the radio station light is on?/ just totally muted.. I tried the am station and nothing at all no noise no sound and that is without using the rear defroster?/ Have no idea I looked at all the strips on the rear window and do not see any broken one`s but I know my eye`s aren`t as good as they were 40 years ago? lol

[L.Mark]

I've had trouble with mine, when I hit the defrost button I get static and someon told me there is something in the luggage tray that may affect this...I can't remember exactly...maybe the nice person will chime in...

[L.Mark]

Found it!!!!

Fastblack said the isolator module could be affecting mine, maybe yours also...

[malibill]

Thanks , I guess I will see about the isolator module?? I know Fastblackmerc knows what he is talking about I just picked up one of his upgraded bcm `s and it works perfect.. I just don`t know enough about these cars really just got it 2 months ago and been trying to use it as much as I can, a lot of fun to drive.. have to do more research would like to fix it.

[GoldPanther]

Don't take my word but I suspect of a faulty antenna module. It's located in the passenger side C pillar. Remove the panel and check, if possible try another one. Said module controls the rear defrost and antenna!

[fastblackmerc]

Don't take my word but I suspect of a faulty antenna module. It's located in the passenger side C pillar. Remove the panel and check, if possible try another one. Said module controls the rear defrost and antenna!

See post #12.

[malibill]

See post #12.
Thanks guess I will check out the isolator under the c pillar.. I am guessing that is a dealer part?/

[GoldPanther]

See post #12.

Oh my bad, I didn't know it was also called isolator module.

[GoldPanther]

Get one from a junk yard, they are the same as the grand marquis afaik

[RF Overlord]

I'm confused...you've given 3 different explanations of the problem. Now you're saying the FM works fine but mutes when you turn on the defroster, and the AM doesn't work at all, whether the defroster is on or off?

[malibill]

No, I thought I said while listening to the fm station if you hit the rear defroster button the sound or music shuts off but the station display is on almost like you hit the mute button.. I then tried the am stations with the rear defroster off and no sound at all ?? Again almost like you hit the mute button?? Sorry if I was not clear ,hopefully that will clear up the symptoms.. Bill

[malibill]

Just an add on.. I was checking it out once again and found that while playing a cd if you hit the rear defroster button the sound still works!! no difference at all and the defroster seems to be working .. .but as before on fm hit defroster and no sound at all if you switch to am no sound regardless if the rear defroster is on or off?? I removed the pass side c? pillar (front closet to windshield) and did not find the antenna isolator under it but that was the front pillar is it the rear pillar I should remove?? Thanks Bill

[fastblackmerc]

Just an add on.. I was checking it out once again and found that while playing a cd if you hit the rear defroster button the sound still works!! no difference at all and the defroster seems to be working .. .but as before on fm hit defroster and no sound at all if you switch to am no sound regardless if the rear defroster is on or off?? I removed the pass side c? pillar (front closet to windshield) and did not find the antenna isolator under it but that was the front pillar is it the rear pillar I should remove?? Thanks Bill

AM will work with a coat hanger as an antenna.

FM needs a better "tuned" antenna.

You removed the wrong pillar trim.

Pillars are from the front of the car....

"A" pillar is located at the windshield and leading edge of the front door.

"B" pillar is between the trailing edge of the front door and leading edge of the rear door.

"C" pillar is at the trailing edge of the rear door and the rear window.

[malibill]

Ok Thanks , Kinda thought I was in the wrong location?? I will give that a look tom, I am guessing as you said it is probably the antenna isolator that is the problem?? Bill