I've been browsing cruise control related threads now for a few days and am not finding anything along the lines of my problem... this may be a repost so pardon my ignorance—I consider my self a newbie to Benz’s but not to wrenching.

The car: 1985 190D 2.2 w/ auto

The problem: cruise will not work until after about 20 to 30 minutes of driving. After that, all functions work as expected at all speeds I've tried.

I've had this car for about 6 months and have slowly taking things off the "to fix" list. From the first day I drove this car the cruise has not worked. About 2 months ago I tried the cruise again and it kicked in but surged the throttle up and down. This made me think I had speedo cable issues but everything checks out and the speedo needle is stable also. Shortly after that I discovered a broken vacuum line…I repaired that hoping it may be the problem but it didn’t affect anything cruise related (It did fix a handful of other issues not surprisingly).

Last week I took the car out and noticed the cruise kicked in after about 30 minutes… I was shocked thinking that the throttle cable was stuck but after messing with the cruise stalk I discovered that everything was working as advertised. (It can’t get any better than a car that fixes it’s self.) Well it wasn’t to be: the same day I traveled back and discovered the cruise would not work right way but did kick in again after about 20 minutes.

The car is starting to gain my trust so I am taking it on more and more road trips but the cruise control oddity has me wondering WTF is happening…

Any feedback is welcome.

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Matt

'87 - fj60 (mine)
'96 - fzj80 (mine but I let her drive it)
'85 - 190D 201.122; 601.921; 722.403 (mine too)

it's those german gremlins working on your car... leave out some candy.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

My best guess would be the amplifier (cca), located under the plastic floor tray below the glove box.

Jim

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2005 C240 4matic wagon (daily driver)
87 190D - 225K (on loan)
85 190D - 312K (on loan)
2011 Subaru Legacy AWD (Wife's)

I was starting to think I had some bad voodoo

so is the amp something I can test?...I've read tons of things about the actuator and the speed sender but the amp seems to be just pull and replace deal... $$

I thought maybe this was a common issue with a well documented repair.

thanks for the replies,

Matt

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Matt

'87 - fj60 (mine)
'96 - fzj80 (mine but I let her drive it)
'85 - 190D 201.122; 601.921; 722.403 (mine too)

I am so glad that you posted this. I was beginning to think us W201 folks are considered the lesser step-children of the Benz owners family. My cruise shows interestingly similar behavior. If I drive only a little bit before I get on the freeway the cruise kicks in just fine when activated. Once I shut it off it never really comes back. I have tried all of the options you mentioned as well as wiggling the cruise control lever in all kinds of directions to no avail. Weirdly enough, sometimes after not being successful in getting it back on I will give up and then just as I am approaching my exit, it kicks in all by itself without even touching the lever. This is a spooky detail that I have yet to explain other than the cruise control amplifier mentioned in one of the replies to your post. My father (a 240D owner) calls it "the brain" and I have to agree that the "brain" in my 190D 2.5 A/T has Alzheimer's.

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327K on 1986 W201, 602.911, 722.414 2.5 190D ("The Red Baron")
139K on 1993 W124, 104.942, 722.433 2.8 300E ("Queen")

http://farm5.static.flickr.com/4081/...0bb92d3c_m.jpg http://i370.photobucket.com/albums/o...g?t=1325284354

Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.
- Albert Einstein

take a walk down memory lane...

There are specific procedures to check the actuator. If the motor functions properly and the current draw is within limits, the problem is the amplifier, by default.

There are no decent tests for the amplifer without a full test bench.

Somewhere I read recently (on this forum, I'm sure) that somebody removed their amp and just did a thorough cleaning of the brass terminals where the harness plugs into it. I think he said he used a small drill bit in the 'holes' or the female side of the connection and actually turned/twisted it with his fingers. Reported that after putting it back together the crazy thing (cruise control) back together that it WORKED!!! Probably do a search and find it...

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Dale