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

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-03-2017, 05:16 PM
Registered User
 
Join Date: Jan 2015
Location: Quebec City, Canada
Posts: 92
190E charging/battery/alt issues

The car is a 1992 190E 2.3. It has been parked for about 1.5 years and in april I put it back together. During the 1.5 years, I did a lot of repairs on it like the suspension and also some welding to remove rust. I had the battery out of the car when welding and I was putting the ground strap close to the areas I was welding on. The car has a new battery since I "resurrected" it and I changed the alternator's voltage regulator/brushes 2 years ago but the car only covered about 10k miles since then.

The car started all the time with the new battery. I didn't drive it much, but it always started. This week I finished all the tuning and solving all the little bugs and I drove it to get it aligned. The shop had to jump start it to get it out of the shop, and I had to jump it again to drive it back home. It drove the 10 mile drive home OK. As soon as I parked it and shut the engine off, It wouldn't start anymore. Not even one turn or anything.

I tested the battery/alternator today after jumpstarting it:

Alternator output at idle (after revving the engine to about 3K once): 13.1 V
Battery voltage at idle: 13 V
Battery voltage after turning car off: 12.8 V
Battery voltage about 15 minutes after shutting the car down: 11.9 V

I tested parasitic drain and it looks good (almost nothing)

I tried disconnecting the battery + while the car was running and although the idle dropped for about a second, it was OK.

I had to have my jumper car run for about 10 minutes to get the Merc to start. As soon as I shut it off, it wouldn't start back up again.

Any thoughts?


Last edited by Rocambolesque; 06-03-2017 at 07:04 PM.
Reply With Quote
  #2  
Old 06-03-2017, 05:43 PM
Registered User
 
Join Date: Jul 2013
Location: Austin
Posts: 412
I'd take the battery out and take itt to an auto parts store and have them test it.

13.1v sounds low for alternator output. My alternator was not charging well after the car sat for a year. Turned out the drive belt was loose. It wasn't squealing either.
Reply With Quote
  #3  
Old 06-03-2017, 06:03 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 4,078
R:

Your quote:
I tried disconnecting the battery + while the car was running and although the idle dropped for about a second, it was OK.
I had to have my jumper car run for about 10 minutes to get the Merc to start. As soon as I shut it off, it wouldn't start back up again.
Any thoughts?


1) The battery disconnection while running caused a large voltage spike system-wide. It is quite likely that some of the more sensitive electrical components of the car have been damaged by the spike. The OVP relay affords some protection, but was not designed for this case. The ECU and the EZL are possible victims, as is the fuel pump relay, and the ABS controller.

2) Try reducing the size of your pics; the post is very wide as a result of the oversize pics.
Reply With Quote
  #4  
Old 06-03-2017, 06:09 PM
Registered User
 
Join Date: Dec 2006
Posts: 3,941
First of all, never remove either the battery or alternator unless the engine is off. That's is a good way to turn a battery problem into a battery and alternator problem.

Second, when you weld, it's a good idea to unplug the alternator as well as the battery. Stray current finds it's way through the wiring and ends there for some reason.

From the description, my best guess is that you have a bad battery, which can happen just from it sitting around. Easiest thing to do is to temporarily install the battery from another vehicle and see if you get better charging voltage. You'll probably see more than 13.8V. If it's not the battery, then take the alternator into a parts store and have them check it on the machine. It could be a bad diode.
Reply With Quote
  #5  
Old 06-03-2017, 07:11 PM
Registered User
 
Join Date: Jan 2015
Location: Quebec City, Canada
Posts: 92
Quote:
Originally Posted by Mxfrank View Post
First of all, never remove either the battery or alternator unless the engine is off. That's is a good way to turn a battery problem into a battery and alternator problem.

Second, when you weld, it's a good idea to unplug the alternator as well as the battery. Stray current finds it's way through the wiring and ends there for some reason.

From the description, my best guess is that you have a bad battery, which can happen just from it sitting around. Easiest thing to do is to temporarily install the battery from another vehicle and see if you get better charging voltage. You'll probably see more than 13.8V. If it's not the battery, then take the alternator into a parts store and have them check it on the machine. It could be a bad diode.
Thanks about the heads up about unplugging the battery, I read that somewhere else and didn't think any further... Now I know, I just hope I didn't damage anything else. Also, next time I weld, I will unplug more than just the battery.

OK I'll test it with another battery, but even the battery that's in it right now is new and didn't sit around very much (I drove the car every 2-3 days even if it wasn't long drives). If it's not that, then I will take out the alternator to have it checked.
Reply With Quote
  #6  
Old 06-03-2017, 08:03 PM
Registered User
 
Join Date: Jul 2013
Location: Austin
Posts: 412
"It is quite likely that some of the more sensitive electrical components of the car have been damaged by the spike. The OVP relay affords some protection, but was not designed for this case. The ECU and the EZL are possible victims, as is the fuel pump relay, and the ABS controller."

I didn't know this, but if you even jump start these cars you are supposed to turn on the headlights to absorb some of the amperage spike.
Reply With Quote
  #7  
Old 06-03-2017, 09:29 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
I'd suspect a bad battery. Since the voltage is staying up above that of a fully charged battery at idle, the alternator is at least trying. Since your battery voltage drops a full volt just sitting there for 15 minutes, either something is drawing a MASSIVE amount of power or the battery is toast.

A bad battery can draw down a good alternator and make you think that alternator is the issue. Leave it there long enough and the alternator WILL become the issue.

Given your charging voltage, the battery should at least be attempting to charge. Since it won't even turn the car over it's junk.
Reply With Quote
  #8  
Old 06-04-2017, 12:44 PM
Registered User
 
Join Date: Sep 2004
Location: Seattle
Posts: 1,971
Quote:
Originally Posted by Rocambolesque View Post
Battery voltage about 15 minutes after shutting the car down: 11.9 V
As others have already said, battery, and this is the clue. The cause is letting the battery sit uncharged for a couple of months. Lead acid batteries don't like that.

As far as disconnecting the battery while running, yeah, that is a no-no. As said, it causes a voltage spike sometimes called "load dump". In theory, the electronics of the car are supposed to be designed to tolerate it. In practice they may or may not. Hopefully you dodged the bullet on that. Good luck.
__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra
Reply With Quote
  #9  
Old 06-04-2017, 12:57 PM
Registered User
 
Join Date: Jan 2015
Location: Quebec City, Canada
Posts: 92
Quote:
Originally Posted by mpolli View Post
As others have already said, battery, and this is the clue. The cause is letting the battery sit uncharged for a couple of months. Lead acid batteries don't like that.
No no. The car sat for a year and a half with another battery. I put a new one in it (which is the one we are suspecting that is bad) when I rebuilt the car 2 months ago. It ran well and started all the time from that time until now. I didnt drive the car much because it wasn't aligned and I had issues with the brakes. I only drove it to pick up my mail and do stuff like that, maybe once every 2-3 days. It didn't sit uncharged for 2 months. The car started to act up this week when I picked it up from the shop. It started by itself (weak start, but it still started) the morning I drove it to the shop.

Also, I went to test the battery today. They read about 11.7 volts on it (same as yesterday) and only 28 amps?! I'm still in the dark because this seems to be a bad battery, but it is low on charge and the alternator was only outputting 13.1 V.

Also, is a 80A alternator from a 2.6 bolt-in replacement for the 70A in my 2.3?
Reply With Quote
  #10  
Old 06-04-2017, 12:58 PM
Registered User
 
Join Date: Mar 2009
Location: San Diego
Posts: 3,537
I would put a new or fully charged battery in and measure the voltage again at idle You should get at least 13.5 or higher. 14v if rev to 3k rpm, you measured it at 13.1 which is low. I suspect it is the alternator which never charged the 'old' battery.
__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
Reply With Quote
  #11  
Old 06-04-2017, 03:07 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,025
13.1V will still charge the battery. Maybe not to 100%, but it will sure be higher than the 11.7V you're getting out of it. When the engine is revved, you should be at 13.5V or higher. With a garbage battery installed, the alternator is going to be under some major strain trying to charge it back up. At idle, you're well below the rated amperage capacity as well. Those two things together add to up to a less than ideal charging voltage.

Get a new battery. If the one you have isn't very old, claim it under warranty.
Reply With Quote
  #12  
Old 08-09-2017, 10:28 PM
Registered User
 
Join Date: Jan 2015
Location: Quebec City, Canada
Posts: 92
Problem solved: it was the alternator. I put a rebuilt one in and now the thing holds a charge. Replacing the battery might have not been necessary after all!
Reply With Quote
  #13  
Old 08-10-2017, 05:37 AM
optimusprime's Avatar
Trevor Hadlington
 
Join Date: May 2014
Location: Worcestershire in England
Posts: 1,453
Is the charging light on when you first switch on the ignition ?. If not the bulb will need replacing .It makes up the circuit .No bulb no charge going in to the battery . Thats if the problem persists.

Reply With Quote
Reply

Bookmarks

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 09:23 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page