Cruise Control Actuator

[Steve N L]

I have a 1988 300CE. My cruise control cuts out every few minutes. My manual gives almost no information about diagnosis of cruise control problems. Pelican Parts has a great tech article about how to replace the cruise control switch on the steering column. Pelican also sells the cruise control actuator. I've been crawling all over my car looking for the damn actuator. Where exactly is this thing? It isn't near the throttle body. I don't see it near the engine. A cable runs from the throttle over the bell housing to some place on the right side.


Where can I find the Cruise control actuator?

[BAd124]

Just came across this. For future reference it should be under the air filter cap on the M103

[porkface]

every bloody time i messed with that generation cruise setup, it was always the amp. we had the oe tool for testing, which replaced the amp and then you push the buttons for whatever function. never, ever had any other part fail. good luck, chuck.

[BAd124]

I replaced the control unit (amp) last year and it seemed to work great. This year I took her out of storage, gave it a try and it worked on the HWY. Tried it again a week later and nothing, not even an attempt to engage

Coincidentally when it was working I was getting this odd "surging" while decelerating (with CC off) while coasting, almost like I was hitting the gas peddle.
That has since stopped along with the CC so it must be related somehow

[cmac2012]

I have a 300 D, I don’t usually come to this forum, ain’t no gasser can teach me nothing. He said tongue in cheek.

I miraculously found my car with 129K in 2019 on the lot of an Indy mechanic outfit in Eugene, Oregon. It had a lot of problems, but the cruise control has worked from the beginning. Except it cuts out about every 45 minutes to an hour approx - It’s as if I had just tapped the brakes, it disappears. Comes back real quick. I’ve heard from a lot of guys that usually usually it’s the amp. Sometimes the diesels have different amps, maybe always, not sure.

[BAd124]

Following up on this, it seems to be very random when this thing actually works. Last week on a drive to my parents it worked flawless. On the way back it would engage normal for about 5 secs, then accel hard, then quit each time I tried it.
This week, back to nothing happens at all. Beginning to think its completely possessed