R129 failing audio

[cricomac]

My recently acquired 91 500SL has a most annoying intermittent audio problem. Much of the time, there is no sound output from the bass at all. Occasionally, however, bass returns--but if this happens, either the right or left channel completely drops out simultaneously. On rare, brief occasions, everything works simultaneously. These problems occur even when the car is standing still, so I don't think it's just a loose connection somewhere. It is the stock Becker system. Any ideas on my best way to troubleshoot this? Has anyone experienced anything similar?

[Cleeve]

Hi cricomac,
From what you have described it sounds like the Tuner Pack (BE-1432) has amplifier problems as well as the Amplifier under the passenger floor panel that controls the Bass. Let me know if you need my help in getting these items tested and repaired. You can contact me via my Web site at: www.lajollaaudiorepair.com

Cleeve Morrison
La Jolla Audio Repair

[tecqboy]

I had this exact same problem. 91 300 SL with Becker system. Solution: Clean all the connectors between the amplifiers and the speakers. Use a good contact cleaner spray. These are 2 pin DIN style and loosen up over time. That is, they don't fit tightly due to loosing spring tension. Also check the input from the speed transducer. There are connectors in the trunk at the receiver head, in the console at the controller head, and at the bass amps under the seat. This system is spread all over the vehicle. Tod

[cricomac]

Thanks to both of you for the help. I've checked/cleaned the connections for the tuner unit in the trunk as per suggestions, but have not yet located the bass amp in the passenger compartment. I found the compartment along the firewall by drawing the carpet back (with the provided handle) and removed the black plastic protector plate, but saw nothing resembling an amplifier. Is it in that location or somewhere else? BTW -- cleaning the contacts at the tune side did not help.