The flasher will whine/buzz if there's a load on it even when the switch (to the lamps) is off. I found this out when I hooked up an auxiliary clacker relay in the SL, but did it 'wrong'.
In normal operation it flashes when it sees a full load on it, and waits quietly until it does see such a load. Remember that it's calibrated to flash faster under a too-light load, as a lamp-out warning. Taken to extremes apparently it can get to the buzz/whine point. Pull the flasher and measure the resistance from the output socket pin to ground, there should be infinite resistance unless a turn signal or hazard switch is engaged. I'm guessing it's a leaky/dirty hazard switch that's letting some current, at a non-illuminating level, travel through it. Regardless, I'm thinking you'll find a parasitic leak, and your job is to chase it down and kill it. -- Jim ---------------------------------------- From: "Bill R" <billr32...@comcast.net> Sent: Saturday, August 08, 2009 6:12 AM To: "Mercedes Discussion List" <mercedes@okiebenz.com> Subject: Re: [MBZ] Dash console dead - 1981 300SD I didn't know the relays were interchangeable. I had noticed that there seems to be more pins than metal contact sleeves in some of the sockets, and wondered if I had knocked one loose during the [relatively gentle] cleaning. I'll take a look at the numbers on the relays. Thanks - Bill -----Original Message----- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of MG Sent: Saturday, August 08, 2009 8:09 AM To: Mercedes Discussion List Subject: Re: [MBZ] Dash console dead - 1981 300SD Maybe a relay problem since it changes when you messed with that relay. I would try switching another relay of the same type from another position and see if it improves. If not then look for a bad contact on the back of the instrument panel. Possible loose wire or even a broken trace on the board. A loose wire can make a buzzing noise when the power sparks across the gap. Check all the contacts in the plug on the back of the board. Manfred Message: 7 Date: Fri, 7 Aug 2009 16:47:28 -0400 From: "Bill R" Subject: Re: [MBZ] Dash console dead - 1981 300SD Guess I should get a bit more specific. The temp, fuel, oil pressure [pegged at the top] speedo, tach and blinkers are dead. The clock. odo and flashers do work. BillR _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://okiebenz.com/pipermail/mercedes_okiebenz.com/attachments/20090808/a441de4a/attachment.html> _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com