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This car was recommended by a mechanic. From my queries, the problem started with an ABS light coin on intermittently and eventually lit permanently. Then battery started to drain overnight to the point it had to be replaced. Mechanic checked alternator and said it was not charging so alternator was changed. The following day, battery was drained again. When I drove over to check the vehicle, I did a visual inspection and nothing seem to be out of the ordinary; alternator was charging. So I did the old fashion way of checking for parasitic drain : disconnecting B (-) and doing ampere check; it showed 4.35 A and indeed there was drain; started pulling out fuse until fuse 23 (A/C temp control and fan blower)showed a drop from 4.35A to 1.4A. I advised owner not to plug back the fuse and observe if battery will drain again; he called and said the battery was dead again. Today I drove over and scanned for fault codes and it showed a lot of DTC's, from headlamps to tail lights, etc. However It did not show an ABS fault code though the ABS light was lit.
Question is : did the dead battery lead to this unusual behavior - no check engine lights on but showed stored faults such as
1.B1630 - right low beam and right front headlamp faulty;
2.B1633 - left side marker lamp defective;
3.B1017 - wiper motor is not within the park position
4. C1013 - terminal 30 undervoltage...and a lot more
all these components are working...anybody who has experienced a similar problem? I'd appreciate some inputs or directions to go. Thnks.
I, recently, had a rear wiper motor that was not in the "park / home" position causing a parasitic draw. The wiper blade appeared to be in the right position, but was about 1 inch from "HOME". I was observing the draw on the scope when I physically moved the wiper arm that inch and removed a 5 amp draw. I would put the wiper motor through the paces and make sure it is consistently and fully returning to the Off / Park / Home position.
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
pole71 wrote: I, recently, had a rear wiper motor that was not in the "park / home" position causing a parasitic draw. The wiper blade appeared to be in the right position, but was about 1 inch from "HOME". I was observing the draw on the scope when I physically moved the wiper arm that inch and removed a 5 amp draw. I would put the wiper motor through the paces and make sure it is consistently and fully returning to the Off / Park / Home position.
Pretty smart! I wouldn't have thought that could keep a module alive!
Even with A/C blower fuse removed, 1.4amps is way too much current flow. It looks like you may have more going there.
Have you checked a power distribution diagram yet to see everything powered by fuse 23?
The only other thing I can think to bring up would be the time it can take for modules to power down. Most of the service info I've read (for other manufacturers) requires the doors to be locked and the alarm armed with the key fob, and the key moved away from the immediate vicinity of the car. After those conditions have been met, then it can take up to 45 minutes for all the modules to go to sleep.
I know the alternator has been changed but a major suspect with big curent drains is always an alternator diode, the alternator will charge but key off current flows back through the windings.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 8 years 8 months ago by Andy.MacFadyen.
pole71 wrote: I, recently, had a rear wiper motor that was not in the "park / home" position causing a parasitic draw. The wiper blade appeared to be in the right position, but was about 1 inch from "HOME". I was observing the draw on the scope when I physically moved the wiper arm that inch and removed a 5 amp draw. I would put the wiper motor through the paces and make sure it is consistently and fully returning to the Off / Park / Home position.
cool I like it ---
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 8 years 8 months ago by Andy.MacFadyen.
what is the best way to test the diode (other than connecting DVOM red lead to bat post and grounding black lead to body of alternator and observing charging rate, KOER at hi rpm, therefore diode integrity)
Hi Noah...no I have not checked the distribution box but I intend to. I noticed that a rubber lining that prevents water draining down is finding its way to the side of the fuse/distribution box...something worth digging into. Yes I agree that a 1.4 A readout with fuse removed is a red flag. I always find MB and other European behave "mysteriously". I will keep you guys posted on developments. Thanks.
After checking further for parasitic drain, I found the culprit - telephone module was draining at a rate of 7.43 A to about 5.21 A; with such a huge drain no wonder it doesnt take long for the battery to drain. In as much as the owner does not use this gadget, I ask him if its ok to just permanently take out the fuse. I did and let the car sit overnight without detaching the negative cable. The car started with no problem at all. Long story short, this is a FIX...
Hey Robert I'm sure you've fixed it by now but best thing to do on these early w220 s classes is to disconnect each SAM( fuse block) 2 in engine bay and 1 under right side rear seat. These S classes if the minor and major services performed correctly or on time can lead to leaves and debris collecting in the right front air inlet box. There is a drain at the bottom of drain for water that runs all the way under the rear seat on right side. Water will collect and I've seen numerous rear SAMs under water. But unplug the Sam's to isolate with sam has the draw and go from there. Also replaced a lot of door control modules due to draws on these S classes also.
I followed up on this car and customer informed me there was no longer a drain, although when he drove it home thefirst time, engine hesitated momentarily and then drove smoothly (ECM relearning?). He wants me to check his Radio this time as it had no audio. I got me wiring diagram from mitchell and boy did i find those SAMs (fuse and relays),switches and modules located on wheel wells ! Certainly see redflag...I will keep you all posted on this. Thank you euroteknic and I will check per your advise.
hi...this car sent to me, this time for a no audio problem. inspecting trunk, discovered cd changer badly corroded n beyond repair; audio module had slight corrosin but savable. HOWEVER, the problem is ignition wont turn to start. changed FOB battery and battery voltage excellent. anyone experience the same thing?
I'm not sure what happened here, I got a message in my inbox that this thread had been reported to the moderators for some reason?
I would like to remind anyone reading this thread that the report to moderators function is there to let us know if you maybe need a thread moved or deleted, or to let us know of any spam or rude behaviour (of which I am proud to say there has been virtually none! You guys are awesome!).
As for the Benz, sorry Rob. I've never tackled one with that issue. Hopefully someone here has the information you need!
sorry Noah. I wanted to post a FIX on this car but I cudnt see an edit box whete I can post ir. I thought by "reporting", it would send the post as fix...
robert.lesaca wrote: sorry Noah. I wanted to post a FIX on this car but I cudnt see an edit box whete I can post ir. I thought by "reporting", it would send the post as fix...
No problem at all!
I hit the report button all the time on accident, lol!
Stupid mechanics sausage fingers...
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I like it ---
