battery change = loss of radio & carbriolet headrests reset
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2000 c230, 1999 c230, 1994 e320 cabriolet, 1988 560 sl
battery change = loss of radio & carbriolet headrests reset
had the battery replaced on a 1994 E320 cabriolet which resulted in radio not operating and rear headrests (steel) coming up and not returning as well as convertible top no longer working. Thoughts? Thanks.
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Joined: Nov 2002
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From: Massachusetts
2018 GLE350, 2014 G550, 2000 SL500, 1980 TR8, 1995 E320 Cabriolet
I doubt your issue has anything to do with the OVP as it does not supply power to any of the effected systems. OVP failure on your car will result in an ABS light or a no start/engine cut-out condition.
Three things come to mind -
Check your fuses! The old style Bosch tin/lead fuses have a tendency to corrode at the ends and then fail to make a proper connection, especially after a current surge like that that occurs when the battery is replaced (the new battery has to charge in electrolytic capacitors in the various modules). The corroded area on these fuses is so subtle that it often can't been seen visually.
The proper fix for long term reliability is to replace the fuses with the all copper versions, but at the very least, remove, inspect, and clean the current fuses. Prophylactically replace fuses 9, C, and the 16 amp fuse in the auxiliary fuses holder (on the right strut mount).
Once you've covered the fuses, disconnect the battery for about 10 minutes and then carefully reconnect it. Don't let the terminals "arc' - slam it on in one move. This is a common mistake that many untrained grease monkeys make - the arcing or "contact bounce" can cause glitching for modules that have a battery supplied memory circuit (like all of your affected systems). This procedure should allow them to reset. If you have the OE radio you will have to re-enter the radio code afterward.
lastly, said grease monkey may have accidentally connected the battery in reverse at the beginning. If corrected before any attempt to start the car, this would also only affect battery supplied modules, but unfortunately, often the damage is permanent. I doubt that this is your issue, but I reference it for completeness.
Good luck,
- FD
Three things come to mind -
Check your fuses! The old style Bosch tin/lead fuses have a tendency to corrode at the ends and then fail to make a proper connection, especially after a current surge like that that occurs when the battery is replaced (the new battery has to charge in electrolytic capacitors in the various modules). The corroded area on these fuses is so subtle that it often can't been seen visually.
The proper fix for long term reliability is to replace the fuses with the all copper versions, but at the very least, remove, inspect, and clean the current fuses. Prophylactically replace fuses 9, C, and the 16 amp fuse in the auxiliary fuses holder (on the right strut mount).
Once you've covered the fuses, disconnect the battery for about 10 minutes and then carefully reconnect it. Don't let the terminals "arc' - slam it on in one move. This is a common mistake that many untrained grease monkeys make - the arcing or "contact bounce" can cause glitching for modules that have a battery supplied memory circuit (like all of your affected systems). This procedure should allow them to reset. If you have the OE radio you will have to re-enter the radio code afterward.
lastly, said grease monkey may have accidentally connected the battery in reverse at the beginning. If corrected before any attempt to start the car, this would also only affect battery supplied modules, but unfortunately, often the damage is permanent. I doubt that this is your issue, but I reference it for completeness.
Good luck,
- FD
