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 ShopForum > Technical Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-04-2010, 09:15 PM
Registered User
 
Join Date: Nov 2010
Location: TX
Posts: 3,253
digital temp display

Hi guys,

Ive been trying to sort out the digital temp display on the 95 E300D - I traced the wiring back to under the fuse box and disconnected the connector, it still showed 136 degrees F. (I read that it should show the minimum when disconnected)

When testing the sensor itself, it shows a resistance of 3.31K ohms in 72 degrees weather. Tested the sensor wiring for a ground input and it sure has negative continuity at the brown wire.

What else did I miss - or is my display shot - Whenever I start the car - it shows 136 degrees and goes out after a minute or so, sometimes it never shows up at all.
Reply With Quote
  #2  
Old 12-04-2010, 10:25 PM
Aquaticedge's Avatar
Bump on a log
 
Join Date: Nov 2009
Location: See Biography
Posts: 3,148
could just be the screen controller. they do go bad
__________________
hum.....
1987 300TD 311,000M Stolen. Presumed destroyed
Reply With Quote
  #3  
Old 12-04-2010, 10:54 PM
is thinning the herd
 
Join Date: Mar 2010
Location: Columbus, Ohio
Posts: 3,210
Having the same exact problem with my 92. Read higher and higher every day, now its just stuck at 136* and sometimes the screen is lit up but blank.

No help, but you're not alone.
__________________
Current: 68 280SL, 70 300SEL 3.5, 72 350SL, 72 220, 87 300D, 87 200TD Euro, 90 190E 2.0 Euro, 06 E320 CDI, 72 220D, 72 280SEL 4.5

Ford F250 PSD / Nissan GTR / Celica GTFour / Dodge Dakota / Land Cruiser Diesel / Toyota Soarer GTT / Skyline GTS / Rover Mini

40+ previous Benz's
Reply With Quote
  #4  
Old 12-04-2010, 11:01 PM
Aquaticedge's Avatar
Bump on a log
 
Join Date: Nov 2009
Location: See Biography
Posts: 3,148
Mines convinced it's either 1 degree out or +135
__________________
hum.....
1987 300TD 311,000M Stolen. Presumed destroyed
Reply With Quote
  #5  
Old 12-04-2010, 11:23 PM
Jeremy5848's Avatar
Registered Biodiesel User
 
Join Date: Mar 2006
Location: Sonoma Wine Country
Posts: 8,390
The sensors rarely go bad -- they are simply a resistor "bred" to be especially heat sensitive. At the display, if the sensor wire is open, the display should show a maximum low temperature (-36F or so). If the sensor wire is shorted to ground, it will show maximum high temperature (+130-something F). The display is programmed to go blank if the reading sticks at either high or low for more than a few minutes.

The usual culprit is the LCD display -- it turns black (all or part). The electronics that translates the sensor resistance into a digital signal for the LCD can also fail. The LCD can be swapped out if you have another and can carefully disassemble the display.

The display electronics is pretty much non-fixable, especially the later versions with a high degree of integration. For all of them there are no internal schematic diagrams available, at least none I've ever seen.
__________________

"Buster" in the '95

Our all-biodiesel family
1995 E300D (W124) . .239,000 miles My car
1996 E300D (W210) . .313,000 miles Wife's car
Santa Rosa population 170,685 (2012)
Total. . . . . . . . . . . . 722,685
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970
Reply With Quote
  #6  
Old 12-05-2010, 12:00 AM
Banned
 
Join Date: Nov 2001
Location: Cape Cod Massachusetts
Posts: 1,427
If anyone figures out their display module is "kaput", I have good tested used replacements available.

http://www.peachparts.com//shopforum/showthread.php?t=263652
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 04:42 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page