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 > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 12-26-2007, 11:22 PM
Registered User
 
Join Date: Jan 2007
Location: Taylorville, Il.
Posts: 157
Cruise Control

Well I thought I had the cruse fixed, took the servo apart and it was trashed inside so I got another used one and was able to make 1 good one from the parts, motor moves, ohms correctly, solenoid pulls in, pot reads as it should threw the scale, so it should be in working order. so then I checked the switch on the, it all works as it should, so I moved on to the amp and I found a couple problems in there, I found 2 resistors so far that are toasted. What I need is some one that has a amp thats not toasted where mine is to tell me what the color bands are supposed to be on the 2 toasted resistors you can see the 2 in the picture I posted

Attached Thumbnails
Cruise Control-closeup.jpg  
__________________
82 240D (82 300D drive train)
Reply With Quote
  #2  
Old 12-28-2007, 12:41 AM
Registered User
 
Join Date: Jan 2007
Location: Taylorville, Il.
Posts: 157
well I think I got it figured out on my own, one is brown green brown, and the other is brown black brown, I replaced them both and now it does work but at speed its jurkey it will speed up slow down speed up slow down so Im not sure if I have a dirty/poor signal from the speed sensor, a bad cap or another component thats floated from its valve, if I have a high resistance solder joint, or my other thought when I cleaned and rebuilt the cruse control actuator if the some of the grease got in the variable resistor and it just needs to wear off
any thoughts at to what I may need to do ?
__________________
82 240D (82 300D drive train)
Reply With Quote
  #3  
Old 12-28-2007, 01:56 AM
dieseldiehard's Avatar
Dieseldiehard
 
Join Date: Oct 2002
Location: Bay Area No Calif.
Posts: 4,349
Those resistors don't (didn't) look toasted to me, I think you are seeing the varnish used for waterproofing has discolored. Did you read the resistors on a Ohmmeter before replacing them?
The resistors that usually fail are really burned and they are at the dc input to the module and have a capacitor to ground, that cap tends to short then it draws excessive current thru the series resistor, which as I recall is a 10 Ohm resistor and it gets charred.

Troubleshooting this sort of thing is difficult without a lot of test equipment on a workbench. I usually send my modules to General Dynamic Labs (GDL) for verification before I open one because if it does go to them later they may refuse to accept it if the seal was opened and it was "messed with".

see this thread:
Cruise Control - Hesitations
__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!
Reply With Quote
  #4  
Old 12-28-2007, 09:22 AM
Registered User
 
Join Date: Jan 2007
Location: Taylorville, Il.
Posts: 157
the one that has the case blown open in the picture was for sure bad it was it was almost a dead short, and the other with the side burnt you can see in the picture is was open so it was also bad. I have plenty of electronic test equipment O-scope, frequency counter, function generator, variable power supply, bench top multi meter, cap meter, soldering station, desoldering equipment, a few draws of new parts, and a box full of old boards for spare parts. So testing and repairing things shouldnt be to much of a problem just takes allot of time with out a schematic
__________________
82 240D (82 300D drive train)
Reply With Quote
  #5  
Old 12-28-2007, 08:35 PM
dieseldiehard's Avatar
Dieseldiehard
 
Join Date: Oct 2002
Location: Bay Area No Calif.
Posts: 4,349
OK, I see the one with a cracked body, I take back what I said about not overheated, its clearly been overheated!
hmmm I wonder if there isn't something else shorted?
I've heard that a shorted actuator will cause a failure on the module board. I would suspect the cruise actuator too. You could snag a module off a wrecked car at a junkyard cheap and try it, but if the actuator is shorted then it too might get damaged.
__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!
Reply With Quote
  #6  
Old 12-28-2007, 08:44 PM
Registered User
 
Join Date: Jan 2007
Location: Taylorville, Il.
Posts: 157
the actuator that was on the car to begin with looked like it had a small explosion go off inside of it Im sure its what killed the resistors, I replaced the actuator with a used one that I took apart, cleaned and tested the actuator works just fine now reads as it should and works as it should, Im now Im just working on trying to get it to be smoother when its working it tires to adjust it self all the time speeds up then it holds for a moment then it will slow down
and hold again for a moment and then it starts all over again over and over again it never actually holds the constant correct speed

__________________
82 240D (82 300D drive train)
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 02:55 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2023, 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