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 02-26-2004, 12:53 PM
JenTay's Avatar
Registered User
 
Join Date: Dec 2003
Posts: 555
cruise actuator

is there a quick and easy mityvac-way to check this?

__________________
Jennifer
90 350sdl
Reply With Quote
  #2  
Old 02-26-2004, 02:22 PM
Rick Miley's Avatar
Spark Free
 
Join Date: Jun 1999
Location: Land O Lakes, FL
Posts: 3,086
Not that I know of. But it's much more likely that your amp is the problem, not the actuator.
__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References
Reply With Quote
  #3  
Old 02-26-2004, 11:30 PM
Registered User
 
Join Date: Sep 2003
Location: S.F. Bayarea
Posts: 196
There is always exception to the rule.
When I bought the SD, cruise was bad. Tried measure the actuator for motor open circuit and variable resistance etc. The variable resistance is not functioning right. Opened it up, and found the shaft was worn. A used actuator cures it. I was lucky that the cruise controller worked.
__________________
Shane83SD
Reply With Quote
  #4  
Old 02-27-2004, 12:14 AM
ForcedInduction
Guest
 
Posts: n/a
If I could make my speedometer work, I would know if my cruise eworks.

Any way to bypass the speedo or make a potentiometer to take the place of the amp and speedo?

I would imagine a rheostat and toggle switch could be rigged to power the actuator direcly. Could this work?
Reply With Quote
  #5  
Old 02-27-2004, 01:29 AM
Registered User
 
Join Date: Sep 2003
Location: S.F. Bayarea
Posts: 196
Hi 82-300TD

Spending time and effort to "re-invent" the cruise seems like rather involved task. It has to be able to over-power the pedal linkage and design a feedback control loop for desired cruising speed....
__________________
Shane83SD
Reply With Quote
  #6  
Old 02-27-2004, 01:38 AM
ForcedInduction
Guest
 
Posts: n/a
Quote:
Originally posted by shane83SD
Hi 82-300TD

Spending time and effort to "re-invent" the cruise seems like rather involved task.
Not reinvent, but bypass the cruise control amp and control the stock actuator directly by manualy activating the lock and changing the current/voltage sent to it like the amp does. It's not automatic, but it will save your foot alot of strain.
Reply With Quote
  #7  
Old 02-27-2004, 02:55 AM
Registered User
 
Join Date: Mar 2003
Location: Chimacum, WA
Posts: 80
One quick diagnosic test.

Can you make your Benz accelerate with the cruise lever? If so, then your actuator is working properly. If not, then your problem may be with one or more components of the system, including the actuator. On a 240D I once owned, I could accelerate and decelerate with the lever, but the amp had no short term memory whatsoever.

Phil
'84 Euro 300D, peasant class, no cruise
'85 300D, drives itself
Reply With Quote
  #8  
Old 02-27-2004, 08:35 AM
engatwork's Avatar
Registered User
 
Join Date: May 2000
Location: Soperton, Ga. USA
Posts: 13,863
Ya'll keep in mind that the one Jennifer is asking about has the vacuum actuator instead of the electric. Over the next month I am going to try to get the one in my '81 working and will post whatever I find.
__________________
Jim
Reply With Quote
  #9  
Old 02-27-2004, 01:29 PM
AdaptaXion
Guest
 
Posts: n/a
'81 cruise...

Speaking of '81 cruise control....

Mine will accelerate and decellerate per the control lever. It will also accept a set speed. However, a few seconds after the speed is set, it will accelerate to 3 mph or so over the set speed, and then return to the set speed, it cycles back and forth like this until deactivated.

There is both a vacuum component and an electric component to my system. I wondered if some cable or linkage was just loose - so I tightened the little plastic nut that tensions the control cable to the vacuum unit. This helped a little, but not much.

I now suspect that the electric control unit is the problem. Its an expensive unit to replace, so I'm holding off.

My speedo occasionally bounces around by 2 or 3 mph around my actual speed. This might be related, yet its strange that it only happens occasionally, and not very often. Perhaps a grounding problem (?).

Engatwork - I'm very interested to hear how your cruise repair job turns out.

Anyone with cruise control problems - do you also have a problem with occasional speedo fluctuation?

-Zach
1981 300D (220 k Miles)
Reply With Quote
  #10  
Old 02-28-2004, 02:12 PM
Wes Bender's Avatar
Retired User
 
Join Date: Mar 2001
Location: Alpine, AZ / Green Valley, AZ
Posts: 733
Zach - I have a minor fluctuation in my cruise control. I also have a slight speedometer needle wobble (intermittantly). I'm changing the speedo cable this weekend and will post the results.

82-300TD - I don't think you can "fool" the cruise amp with a rheostat. The signal that it reads is a series of pulses, not changing resistance. Maybe you could mount a magnet on the driveshaft and a reed switch nearby that would pulse in time with driveshaft speed. Going to all that trouble, though, you might just as well fix the speedo problem....

my $.02,
Wes
Reply With Quote
  #11  
Old 02-28-2004, 02:24 PM
ForcedInduction
Guest
 
Posts: n/a
Quote:
Originally posted by Wes Bender
82-300TD - I don't think you can "fool" the cruise amp with a rheostat.

I don't think I'm giving the right idea. I will control the actuator *directly*, by controling the electromagnet and electric motor inside the actuator via switches.

I'm getting the components today and should have everything in by the end of the week.
Reply With Quote
  #12  
Old 02-28-2004, 02:31 PM
Wes Bender's Avatar
Retired User
 
Join Date: Mar 2001
Location: Alpine, AZ / Green Valley, AZ
Posts: 733
82-300td - My bad. Skimmed your posts too quickly. Let us know how it works.

Wes
Reply With Quote
  #13  
Old 02-28-2004, 03:10 PM
lietuviai's Avatar
Registered User
 
Join Date: Mar 2003
Location: SW WA
Posts: 5,744
I tried to use my CC in my '85 300D last week but after I tried setting the speed it just started accelerating as if it was floored and I was alreay doing 70 at that point. It used to sort of work before that it would keep speed for a short time but then it would start surging by accelerating and decelerating wildly. It would work better when I would be driving on a slight incline but if I was driving on a slight downgrade, forget it. I've tried doing everything suggested in this forum short of taking the amp apart and checking it with a meter. if these things are so unreliable is it worth even going out and buying a new amp if its just going to go bad again in a short time?
Why are these things so quirky and unreliable?
__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012
Reply With Quote
  #14  
Old 02-28-2004, 07:10 PM
Wes Bender's Avatar
Retired User
 
Join Date: Mar 2001
Location: Alpine, AZ / Green Valley, AZ
Posts: 733
You know, after reading all the cruise control threads (and experiencing a few of the problems myself), it strikes me that someone could put together a reasonably priced aftermarket kit to retrofit these cars and eliminate the expensive fixes and to add some reliability. There ought to be some money to be made there somewhere.

Methinks the next time I have a problem with one of the cruise controls in either diesel I'm going to investigate aftermarket.

Funny, the cruise in the Tacoma works perfectly. Course, its only 9 years old compared to 22 on the diesels.

Just my $.02,
Wes
Reply With Quote
  #15  
Old 02-28-2004, 11:54 PM
lietuviai's Avatar
Registered User
 
Join Date: Mar 2003
Location: SW WA
Posts: 5,744
Quote:
Originally posted by Wes Bender
Funny, the cruise in the Tacoma works perfectly. Course, its only 9 years old compared to 22 on the diesels.
My CC in my 11 y.o. Silverado works flawlessly as well as everything else.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012
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 07:08 PM.


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