jkjambo

I only get signal when i'm in city and even that time it's weak. was working great before , i had to change whole heater core couple of months ago, but even after that it was working , i've noticed radio problem after replacing small speakers (in triangle part) , i just changed them with cls ones for couple of minutes, as they are smaller and doesn't fit there, so i then installed clk ones back. i know it couldn't make any damage , but i just noticed weak radio after that.
​I've also changed back panel (which is under rear window), but rechecked wires there and seems like i didn't damaged anyting there. i know there is radio amplifier on right side, but i haven't even touched that too, just checked connection yesterday.
rear window isn't tinted (i know sometimes that causes weak signal) , also checked rear fuse box and non of them are blown,
still changed 7.5 fuse in 15 or whatever it was don't remember number.

So can you guys give me any suggestions? i've read forums, but couldn't find answers


first thing coming in my head is that radio cable is almost deatached from stereo unit itself , i still didn't have time to remove and check it.

Ok thread became too long, so if you guys need any more details just ask

Rudeney

It;s fuse 8 that powers the antenna amplifier, but if it;s blown, you;d have no remote locking, either. It is possible that the antenna amp is failing or has detached from the rear glass so it no longer makes contact with its embedded antenna.

jkjambo

It maybe falling, i don't know, but not deatached, i've checked. antenna contacts is looking good too

do i need new amp to check it? i mean is that known issues with 209?

Rudeney

The heat and vibration of the car is a bad environment for that antenna amp. It's a very common failure on the W203, and since the W209 coupe uses pretty much the same parts, it makes sense that it would be affected, too. The cabriolet is not as problematic because the amp is under the dash and wired with plug connectors to the front windshield instead of adhesives like the rear amp setup.

jkjambo

So you think it maybe antena amp?

one more thing i forgot to mention, rear defroster doesn't work either. But again, lines look good on rear window

xsever

I remember reading somewhere that the antenna and the rear defroster are part of the same circuit so if the defroster is not working, then that's an indication that there's a problem with the rear circuit.

Did you check the fuse?

jkjambo

I've read that too and i'm 99% sure they are related and caused by one thing , and that's a thing i want to find out.
I've replaced 7.5a fuse in rear fuse box in 8 and checked others too, but non of them are blown.
I've also read that it may related with relay too , but in that case i should have low range of key , but it's still same and range is good.

My battery is bad also, i have to change it, but i don't think it can cause that

Anker

Since we are at it I have an "interesting" issue with my Sirius receiver. It claims to lose signal on a fairly frequent basis, but its not related to driving under bridges and in densely wooded areas, it is more random and will occur in wide open spaces, which never happened with any of my other cars that had XM. In those cars a loss of signal was always explainable. It also happens with the same frequency in Florida and Massachusetts, which wasn't the case with my former cars and was explainable by the declination angle to the satellites.

Rudeney

@jkjambo: I think you have a problem with the wiring in the rear glass. I'd remove the C-pillar cabin paneling and see if you can find any obvious issues. The defrost connectors are removable, but like I said, the antenna amp is glued on, and is above the headliner, so it's difficult to see if it is connected. You might try (gently!) pulling the rear edge of the headliner down so you can get your fingers on the amp (which runs pretty much the entire width of the glass). Press on it and see if that improves reception. iI so, it's detached and there's the issue.

@Anker: All MBZ's I've owned with Sirius have had excellent reception. Note that even though Sirius and XM merged, they still use two different satellite technologies. XM uses geosynchronous orbit, while Sirius uses a a series of satellite in a figure-8 elliptical orbit. XM is reception is optimized for Detroit, MI (gee, I wonder why? ) Sirius "should" cover the entire country very well, but there are times of day when the moving satellites will be further away from certain areas, and reception can be compromised by weather and obstructions, even small ones. But this should not last very long and will occur at the same time every day. If your reception problems vary as to time of day, then you may have a bad antenna or wiring issue. You could verify by getting a cheap magnetic Sirius antenna and plugging it directly into the tuner in place of the factory connection. If that solves it, then you know where to look.

BTW, My wife has a new Cadillac XT5 and it has a "native XM" tuner and it drops out all the time!

jkjambo

I've checked there, but didn't find anything damaged, i can ask one guy to borrow me amp from wrecked car and see if it will fix , but these days, maybe after couple of days. But i'm almost sure that it won't fix it ..
I'm thinking about 2 variants :
1) There is some damaged wire(s) under c-pillar panel which corresponds for both amp/rear defroster .
2) there is loose contact inside of dash , either on climat control unit or stereo (or both)
​​​​Anyone have diagram or anything like that? how can i check wires itself? i mean how much Voltage should come from it , ect

Sorry , English is not my native language

Rudeney

Note that installing the antenna amp on the glass is a complex job. The contacts for the wiring in the glass must line up with the contacts on the amp and then you must use a special adhesive to attach the amp to the glass - but DO NOT get the adhesive on the contacts or it will not work!

It would be easy enough to check the wiring for the antenna from the dash to the amp. Just pull the radio head unit out and check continuity from the connector in the dash to the C-pillar junction.

jkjambo

in antena amp i mean this part, not lines itself, offcourse i can't do line part myself

.

Anker

I can't find anything in WIS or EPC that deals with the Sirius antenna. Where does the Sirius antenna plug in? The antenna amplifier or directly into the Comand unit?

Rudeney

@JKJAMBO: Correct, that is the antenna amp. It attaches to the wiring in the glass by "contact" - there are exposed, conductive surfaces parts of the antennas on the glass itself and the amp just sits on them. making contact. A common failure is that the amp unit itself becomes slightly detached from the glass (due to heat and vibration) and then loses contact with these conductive surfaces. This can also happen with window tint jobs where the installer uses a tool to push the tint onto the glass, above the headliner and ends up inadvertently prying the amp away from the glass.

Rudeney

@ANKER: The Sirius module uses a separate, specialized antenna that is not a part of the antenna amp system. On the cabriolet, it's located inside the trunk lid. On the coupe, it's usually placed on the outside of the trunk lid.

jkjambo

But , in mine , antena amp isn't attached to glass, it's on metal top, under the c-pillar part..

DangermouseCLK

Honestly, if your battery is suspect, I would start there and replace it.

Dodgy batteries can affect all sorts of things that you wouldn't connect.

Rudeney

Is your car a W209 coupe, with an external stubby antenna on the glass? If so, the antenna amp is in fact attached to the underside of the glass, above the headliner. If you have an external stubby antenna mounted on the sheet metal roof, then you have a W208, and you should check that forum for better info

jkjambo

Do you really think i don't know model of my car? ) offcourse it's w209 and offcourse it's couple, or i would post it as A or C 209
Anyway i think we just misunderstood each other (maybe because of language barrier). Ok so antena amp , the part i posted above in picture is definitely is above headliner , but i didn't remove headliner , so i'm not really sure about exact position of amp unit itself , i had feeling it was on top of rear side window, but according to you post i'm wrong and it's on top of rear window, so i have to check it again