W210 Electrical Gremlin
 

My 96 E320 with 71K has starting intermittedly displaying a dim SRS light the last week or so and, less frequently, the factory radio will stop playing. I think I saw the SRS light "flash" when I noticed the radio glitch.
A search of this site suggested a failing voltage regulator - I checked battery voltage with the car off and got 12.46 volts and 14.02 at cold idle, so I've tentatively ruled out the regulator. While running, I was able to check the voltage with a dim SRS light and then I restarted the car and the SRS light was out and the battery voltage was the same both times - 14.02.
In viewing the alternator from underneath I note it is a Valeo and not a Bosch. The car has not left me stranded, i.e., the battery has never been flat. Any thoughts where I should next look? The only other electrical issue I've ever had was about 18 mos ago the SRS came on and stayed on. I had it analyzed at an indie I trust and they could not find anything - reset and the problem never came back. If it is something like a regulatator, will I be able to change it out easily as with a Bosch alternator?
Appreciate any wise guidance or thoughts you can share.
Cheers, Denny

I'd bet that the ignition switch is bad. I've seen the unusual SRS light/radio behavior on lots of pre-98 MB's.

Thanks for responding so quickly - on Christmas no less!
Funny you should mention the ignition switch - this morning it was raining cats & dogs and initially the windshield wipers would not work - period. Turned off the car and re-started the car and everything was fine.
Is there is a recommended diagnosis for the switch? Is this much of a chore to replace or is it better left to the professionals?
Cheers, Denny

Replacement of the ignition switch takes about 1.5 hr at dealer & requires 1 special tool.

Thanks MB DOC - one final question - is this just a fluke (doesn't sound like it) and can I expect the new switch to last any longer than the original (had a similar issue with the wipers at around 44K but then it didn't act up for 27K later.
Cheers, Socks E420

I've been having the exact same symptoms for a week or so on my '96 E320. Looks like I'll have to check the ignition switch. Thanks guys.