My AM reception is poor (2004 ML500) but the FM is perfect. Best description I have is a lot of static noise that makes the AM program difficult to hear. For background I only get reception from the strongest of stations, but with poor quality as stated.
There is no background "whine" like one could hear with a bad ground that changes pitch with engine RPM, so I think electrical shielding is ok.
Before I remove the rear hatch plastic covers to take a look I did some reading on the usual culprits on these trucks. They are as follows with my thoughts:
1. The antenna coax cable becomes partially or totally broken in the rubber boot section where the upper right hand hinge is located. I don't think this is the issue since FM is fine. AM & FM share the same coax cable that runs to the head unit.
2. FM/AM Amplifier unit. I guess this could be the failure. Not sure how to test for functionality
3. Antenna Splitter unit. Again this could be the failure. Not sure how to test for functionality.
4. Loose connections and or poor grounding of units 2 and 3. This I can check easily enough.
In looking for parts I found two items with the ID as Antenna Amplifier. Any help on which is which?
The first is part number 1638200089
The second is 1638200289
The trade off is spending the time to attempt to determine if the units are functioning correctly or replace them as the cost in total is about $70 for both used.
In searching BenzWorld I see folks taking out the head unit and all sorts of things to fix poor reception so my plan is to start with the components in the rear lift hatch and see if there is a fault there.
And I do have the wiring diagram for a 2003 ML350 Bose in hand for reference.
Thanks much for any guidance from those that have been there.
There is no background "whine" like one could hear with a bad ground that changes pitch with engine RPM, so I think electrical shielding is ok.
Before I remove the rear hatch plastic covers to take a look I did some reading on the usual culprits on these trucks. They are as follows with my thoughts:
1. The antenna coax cable becomes partially or totally broken in the rubber boot section where the upper right hand hinge is located. I don't think this is the issue since FM is fine. AM & FM share the same coax cable that runs to the head unit.
2. FM/AM Amplifier unit. I guess this could be the failure. Not sure how to test for functionality
3. Antenna Splitter unit. Again this could be the failure. Not sure how to test for functionality.
4. Loose connections and or poor grounding of units 2 and 3. This I can check easily enough.
In looking for parts I found two items with the ID as Antenna Amplifier. Any help on which is which?
The first is part number 1638200089
The second is 1638200289
The trade off is spending the time to attempt to determine if the units are functioning correctly or replace them as the cost in total is about $70 for both used.
In searching BenzWorld I see folks taking out the head unit and all sorts of things to fix poor reception so my plan is to start with the components in the rear lift hatch and see if there is a fault there.
And I do have the wiring diagram for a 2003 ML350 Bose in hand for reference.
Thanks much for any guidance from those that have been there.