Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 02-06-2007, 09:57 PM
Registered User
Join Date: Sep 2003
Location: Santa Barbara, CA
Posts: 471
Question Power loss accompanied by battery warning light

My "new" 500SEL has been great so far, but I just encountered something troubling...

While driving along the freeway this evening, the engine seemed to cut out completely - I couldn't tell if it was even running at all. On the dash, the battery warning light came on.

I turned towards an exit, and six or seven seconds later (coasting at about 35mph) the battery light turned back off and the engine came back to life. No problems getting home after that.

I can figure out most problems with my diesel, but when it comes to this gasser I'm clueless. What happened? Alternator problem? (The headlights and radio never lost power, the battery works fine.) Fuel pump? (That wouldn't explain the warning light.) ...


'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)
Reply With Quote
Old 02-07-2007, 06:54 AM
Posts: n/a
You need to check electrical connections. To begin with make sure that the connector on the back of the alternator is properly seated. Check for loose grounds and loose battery cables. It also wouldn't hurt to pull the voltage regulator from the alternator and make sure that there is still some brush length.

It also wouldn't hurt to do a voltage drop test between the alternator and battery. That would show up any bad or flaky connections.

If the problem comes back and stays a problem instead of fixing itself, check the battery voltage at a fast idle to see if the battery is charging, then go from there.

Good luck,
Reply With Quote
Old 02-07-2007, 07:12 AM
Registered User
Join Date: May 2006
Posts: 130
My uncles car used to do this... It was caused by the battery - starter lead touching the exhaust manifold and shorting out.

'85 500 SEL
'85 928S2
'88 560 SEC
'90 750i
Reply With Quote
Old 02-07-2007, 12:00 PM
Registered User
Join Date: Aug 2006
Posts: 141
500 Sel

If the head lamps didn't dim during this episode I would take a hard look at the ignition control module and fuel pump.

Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 02:23 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page