These cars are fabulous, just a few of the systems like the cruise I covered in this video seem to be shrouded in mystery, I'm trying to cover all the bases and make it easy to understand everything you'd need to in order to keep a w123 (or w126/116/etc cousins) on the road today
Thank you very much! I'm trying to make these videos clear and interesting, the cruise is partially run by wizards I've been told so I'm hoping to demystify it and help everyone get their car back to its original glory without too vigorous use of the parts cannon lol
I thought breaking it up into parts would help narrow things down and isolate each part of the cruise system, it seems daunting at first but it's actually not that awful once you break it down into each section.
Awesome! I had a car that the cruise worked but tended to hunt and surge, I'm suspecting part 3 on the amp would have cured that issue had I dug into it back then but I had much to learn to get to where we're at with this stuff now! Good info to have out there just in case it starts acting up!
Mine is a 1982, I realize I forgot to update the document on the website, Someone else had a different style amp and got it working, I've updated the document now with photos of the older style amp, see if by chance it matches yours!
Oops, I misunderstood what you were asking. my bad. Yes the earlier models used a vacuum pod or something rather than an electronic actuator. I've gathered some info on repairing the amps but have not been able to experiment with the earlier car side wiring and parts.
@@trythistv Thanks very much! I inherited a 1979 300D model. Its something I will check in some weeks. I got to get some vaccum hoses reconnected in the engine bay by mechanic that knows these diesels first. lol
@@truefunk99 Send him over to trythistv.com/w123vacuum/ and see if the vacuum diagram I've made up looks vaguely correct. Its still a work in progress as far as coloring and some of the engine bay stuff, but it may prove useful!
@@trythistv Okay thanks. Even if its correct I will still need some assistance down here in Texas putting things back together probably, haha. Maybe I can see how far I can get....
I think that sounds close enough I suspect it's ok, I've learned some of the actuators are a little different depending on the year and car they were installed in, so the values I've showed may vary slightly from year to year, and the amps vary wildly too, I'm compiling more information that I need to update the document on the website with the extra info I've had contributed. Also, I got your email, I'm double checking some info and I'll send you back info for your amp!
Brilliant..... Watched all three videos and no longer intimidated by the cruise control. I can't see the link on the wiring. Good job though. Cheers from the UK.
I thought it was some kind of magic before, Here is a link to the document directly: trythistv.com/wp-content/uploads/2020/05/version1complete.pdf It's supposed to be available on this page: trythistv.com/cruise-control/ But for some reason the buttons just plain aren't working on there. I'll look into that sometime another day.
@@trythistv thanks for the link. I've got a right hand drive sl r107, so the location of the module may be different. Thanks again anyhow. Keep the great work coming on UA-cam. 😊😊😊😊👍👍👍👍👍👍👍👍👍🤓🤓🤓
My first gut instinct is that the amp would be in a similar location near the brake pedal but being right hand drive could possibly change that. I'm not sure at all, but the cruise system should be similar in terms of how it functions at least! 🙂
Hello. Your videos are awesome BTW. 1985 Mercedes 380SL. I Tested the actuator as you described and had no operation. I opened it up and found that the diode to the solenoid was not allowing current through. I soldered in a new diode, retested and the actuator works perfectly. Cruise still didn't work. I moved on to part 2 and tested the stalk. Everything tested perfect accept the feedback from the actuator. Pin 9 to pin 13 measured 2 ohms (supposed to be zero). I wasn't sure if that would be acceptable. I moved on to part 3 and removed the amplifier. When I took it apart the burnt smell about knocked me over. I looked the circuit board over and only visibly found a resistor that was slightly discolored but that was it. I went ahead and ordered a rebuilt unit from AutoHaus. Just installed it and still no operation. Could the 2 ohms feedback from the actuator cause no operation? Thanks, Kelly's Auto Repair
It could very well be the problem. I would check for corrosion or wire issues, I'm not sure if I have those corresponding pins listed in the pdf, but checking the wires between them as well as testing that circuit directly at the actuator would be my next steps. I know it's a long shot, but I spent more time than I'd like to admit trying to figure out my cruise when the issue was led brake lights I had installed because they're so much brighter, and they do not work with the cruise system at all without some kind of ballast resistor or such installed
I'm waiting for part 3, I have already done that and I have the same issue... I am using quarantine to finally try to get my Porsche 928 S4 cruise control to work. It is also seen.
I'm sitting here editing part 3 right now, Took a test drive the other day and I can confirm my cruise works flawlessly, holds exactly the speed I set it at, 55, 35, it'll hold that speed even up and downhill, doesn't surge or anything. As good as a modern cruise! Hoping to get the video finished up today, then I'll get it uploaded tomorrow on my potato internet, finish up the written instructions in the document on the website, and you should expect the video to go public on friday morning!
@@trythistv Today I have changed the 4 capacitors in the cruise control unit. Unfortunately I can't try it because I have a problem with the clutch pumps, but I hope it finally starts working. It never worked.
If you're electronically inclined, there is a fantastic writeup on the Porsche pelican parts forum I found a while back, it's very detailed to the point that I have not fully read and absorbed it. Here is a link to that writeup: forums.pelicanparts.com/porsche-911-technical-forum/394659-understanding-vdo-cruise-control-amp.html
Any chance that for your next series, you can repair a W123 clock? Mine works intermittently and I'm getting ready to replace the (2) 100 uf 35v capacitors to restore function but I'm no UA-camr [I'll leave that to you] Seriously though, how many W123s on the road today have a fully functional clock? Very few by my estimates.
Now that is an excellent idea. I think my one cars clock works and the other one is right twice a day lol. It appears the most common failure is the caps you mentioned, I'll certainly put that into my plan for future videos! Thanks a ton for the suggestion!
By the way... we both have the same "blue alarm" on the key chain...mine is 1983 astral silver on blue interior... I replaced the amp which i sourced from an eBay good supplier and connected it. No result ...still not working plus the sugnal lights stop working although the bright & wipers are still workin...kindly advice what to do...thanks and be safe (that is why I was asking what the connector on the the bracket of the amp for...
I had an issue once with the ground for the cluster and some electronics behind the dash getting a bad connection that made some of the lights and gauges quirky, I took all the brown wires off the screw they were on, cleaned everything with a brass brush and reassembled and it solved my gauge issues. You've tested the actuator under the hood, and the wiring in this video and replaced the amp and its still not working? any chance you have LED bulbs in your tail lights?
@@trythistv no LEDs (it's tacky even though Kent suggested).... however it is true that when I pulled out the cluster partially since the kick panel was off already, that is when the turn signal lights stopped working. Will follow your advise. One more thing , the fog light indicator on the light switch which I pulled shows that smallest bulb light I think is there in the car world is missing. do you have any idea where to source it? thanks and be safe.
I'm working on editing it, I'm trying hard to make it clear and understandable, the amp is by far the most complicated part, and there is very limited documentation surrounding it, so some things I've been reading on and other things required some trial and error to solve, now I just need to get it together so it all makes sense!
I didn't get a good angle, when you hear me talking about resume, off, accelerate and decelerate I was pushing the stalk that is on the column to those positions
What kind of car do you have? I've suspected that there could be differences in wiring but haven't run across it yet. I made the videos and documents around a 1982 Mercedes 300d, I know some models used slightly different amps, I can try to find out what yours would be if it would be helpful!
@@trythistv thanks for getting back, I just found the information in my documents, according to them, pin 14 is an optional earth which will allow the cruise control to operate at a much slower speed, which to me is just some sort of witchcraft! It's a mercedes 410d...
I ran your tests with the ignition on, engine running, I got 14v every time, but in phase 2 of the test with ignition off I got the following.... Pin 7 to 10 = 5ohms Pin 7 to 12 nothing Pin 10 to 12 nothing Pin 5 to 12 = 37.4 ohms Pin 9 to 12 = 2.8k ohms Pin 9 to 13 = 113 ohms According to your chart that means my actuator motor is shorted to ground, 113 ohms is supposed to be 0, and the nothing readings are supposed to be infinite and my multimeter reads 1, as though the prongs were not even touching anything. I get a 1 reading both when touching and not touching the pins basically. I've absolutely no idea what that means or where to look next (mercedes 410d with vdo tempostat) Update, 1 also means infinite on this particular cheap multimeter! Ignore what I said, although I still don't get why I'm getting the 113 ohms when it should be 0 2nd update... I had 113ohms resistance on 9-13 but the next day it was reading open circuit! 3rd update, I successfully carried out test one with a 12 volt battery, everything works. And in doing so, pin 9 to 13 came back to life but this time it's around 60ohms! What witchcraft is this??
So, 9-13 being off from the normal reading is related to the actuator potentiometer, which is how it senses the "throttle position" of sorts. 113 ohms is very high, even 60 with your new test is also very high, Pins 2 and 3 on the actuator itself are the potentiometer, you could test with a multimeter at those pins and move the arm with your hand to see if the ohms sweeps smoothly or if there are dead spots it could indicate the potentiometer parts inside the actuator have worn out, if the readings are good at the actuator pins, then you may have a bad wire between the actuator and amplifier.
Best information I've had for my 1983 W123 300D Turbodiesel EVER. Crystal 🔮 clear and logical for dummies!!! Mucho Kudos!!!!
These cars are fabulous, just a few of the systems like the cruise I covered in this video seem to be shrouded in mystery, I'm trying to cover all the bases and make it easy to understand everything you'd need to in order to keep a w123 (or w126/116/etc cousins) on the road today
Figured out my actuator solenoid is fine. Just checked the stalk, it’s fine too. Uh oh.
Again, fabulous video. Super helpful. Thank you!
In depth and to the point. Best w123 videos around!!
Thank you very much! I'm trying to make these videos clear and interesting, the cruise is partially run by wizards I've been told so I'm hoping to demystify it and help everyone get their car back to its original glory without too vigorous use of the parts cannon lol
Agreed! Thanks so much for taking the time to make these gems! Love it!
I guess it is quite off topic but does anyone know of a good site to stream newly released tv shows online?
@Jameson Dexter flixportal :)
@Kason Eduardo Thanks, signed up and it seems like they got a lot of movies there :D I really appreciate it!
Based on this excellent video, my 1984, 280SE seems to have the typical CC problem: the amplifier. Moving to part 3. Many thanks.
I thought breaking it up into parts would help narrow things down and isolate each part of the cruise system, it seems daunting at first but it's actually not that awful once you break it down into each section.
Wonderfull job ! My cruise control is working but it would be a piece of cake fixing it with these vids.
Awesome! I had a car that the cruise worked but tended to hunt and surge, I'm suspecting part 3 on the amp would have cured that issue had I dug into it back then but I had much to learn to get to where we're at with this stuff now! Good info to have out there just in case it starts acting up!
These are awesome videos. Removing the amplifier for me was the worst job ever. It is difficult to lay in the car without killing my back lol
It is a miserable spot to get to! At least there aren't a million things holding it in.
Very well done video, thank you
Glad to help! Hopefully it helped you narrow down any cruise issues you had.
I hope you do get the 9 more hands you desire
What year is your vehicle? Seem like the 1976-1980 mercedes w123 cruise control has a different components than the ones from 1981-1985?
Mine is a 1982, I realize I forgot to update the document on the website, Someone else had a different style amp and got it working, I've updated the document now with photos of the older style amp, see if by chance it matches yours!
Oops, I misunderstood what you were asking. my bad. Yes the earlier models used a vacuum pod or something rather than an electronic actuator. I've gathered some info on repairing the amps but have not been able to experiment with the earlier car side wiring and parts.
@@trythistv Thanks very much! I inherited a 1979 300D model. Its something I will check in some weeks. I got to get some vaccum hoses reconnected in the engine bay by mechanic that knows these diesels first. lol
@@truefunk99 Send him over to trythistv.com/w123vacuum/ and see if the vacuum diagram I've made up looks vaguely correct. Its still a work in progress as far as coloring and some of the engine bay stuff, but it may prove useful!
@@trythistv Okay thanks. Even if its correct I will still need some assistance down here in Texas putting things back together probably, haha. Maybe I can see how far I can get....
Excellent! Thank you
Glad it was helpful!
Thank you so much.
Great video ❤❤
Glad it helped you out!
Awesome video! Thanks for sharing. When testing the last set 9 and 13 I had a reading of 3.6 ohms. Is this ok?
I think that sounds close enough I suspect it's ok, I've learned some of the actuators are a little different depending on the year and car they were installed in, so the values I've showed may vary slightly from year to year, and the amps vary wildly too, I'm compiling more information that I need to update the document on the website with the extra info I've had contributed. Also, I got your email, I'm double checking some info and I'll send you back info for your amp!
Brilliant..... Watched all three videos and no longer intimidated by the cruise control. I can't see the link on the wiring. Good job though. Cheers from the UK.
I thought it was some kind of magic before, Here is a link to the document directly: trythistv.com/wp-content/uploads/2020/05/version1complete.pdf
It's supposed to be available on this page:
trythistv.com/cruise-control/
But for some reason the buttons just plain aren't working on there. I'll look into that sometime another day.
@@trythistv thanks for the link. I've got a right hand drive sl r107, so the location of the module may be different.
Thanks again anyhow. Keep the great work coming on UA-cam. 😊😊😊😊👍👍👍👍👍👍👍👍👍🤓🤓🤓
My first gut instinct is that the amp would be in a similar location near the brake pedal but being right hand drive could possibly change that. I'm not sure at all, but the cruise system should be similar in terms of how it functions at least! 🙂
@@trythistv yup, hope so. I will be having a look sometime soon.
I've read your instructions... All I can say is... Brilliant.
How to test glove compartment light & switch and live electric source ...thanks
Great production.....thank you
Hello. Your videos are awesome BTW. 1985 Mercedes 380SL. I Tested the actuator as you described and had no operation. I opened it up and found that the diode to the solenoid was not allowing current through. I soldered in a new diode, retested and the actuator works perfectly. Cruise still didn't work. I moved on to part 2 and tested the stalk. Everything tested perfect accept the feedback from the actuator. Pin 9 to pin 13 measured 2 ohms (supposed to be zero). I wasn't sure if that would be acceptable. I moved on to part 3 and removed the amplifier. When I took it apart the burnt smell about knocked me over. I looked the circuit board over and only visibly found a resistor that was slightly discolored but that was it. I went ahead and ordered a rebuilt unit from AutoHaus. Just installed it and still no operation. Could the 2 ohms feedback from the actuator cause no operation?
Thanks, Kelly's Auto Repair
It could very well be the problem. I would check for corrosion or wire issues, I'm not sure if I have those corresponding pins listed in the pdf, but checking the wires between them as well as testing that circuit directly at the actuator would be my next steps.
I know it's a long shot, but I spent more time than I'd like to admit trying to figure out my cruise when the issue was led brake lights I had installed because they're so much brighter, and they do not work with the cruise system at all without some kind of ballast resistor or such installed
I'm waiting for part 3, I have already done that and I have the same issue...
I am using quarantine to finally try to get my Porsche 928 S4 cruise control to work. It is also seen.
I'm sitting here editing part 3 right now, Took a test drive the other day and I can confirm my cruise works flawlessly, holds exactly the speed I set it at, 55, 35, it'll hold that speed even up and downhill, doesn't surge or anything. As good as a modern cruise! Hoping to get the video finished up today, then I'll get it uploaded tomorrow on my potato internet, finish up the written instructions in the document on the website, and you should expect the video to go public on friday morning!
@@trythistv Today I have changed the 4 capacitors in the cruise control unit. Unfortunately I can't try it because I have a problem with the clutch pumps, but I hope it finally starts working. It never worked.
hi i ask you, are they the same capacitors for the 14 pin amp as for the 10 pin one ????
I believe so, but I don't have a 14 pin amp anywhere I'm aware of to double check
How does the cruise control know the car is going 25+ MPH? My understanding is the cruise control will only engage at 25+ MPH.
If you're electronically inclined, there is a fantastic writeup on the Porsche pelican parts forum I found a while back, it's very detailed to the point that I have not fully read and absorbed it. Here is a link to that writeup:
forums.pelicanparts.com/porsche-911-technical-forum/394659-understanding-vdo-cruise-control-amp.html
Any chance that for your next series, you can repair a W123 clock? Mine works intermittently and I'm getting ready to replace the (2) 100 uf 35v capacitors to restore function but I'm no UA-camr [I'll leave that to you]
Seriously though, how many W123s on the road today have a fully functional clock? Very few by my estimates.
Now that is an excellent idea. I think my one cars clock works and the other one is right twice a day lol. It appears the most common failure is the caps you mentioned, I'll certainly put that into my plan for future videos! Thanks a ton for the suggestion!
First time I've heard of a non functioning clock on the w123 to be honest
My pinout is different...all seems good though... Everything functions at it should just different pins...
76 300d
By the way... we both have the same "blue alarm" on the key chain...mine is 1983 astral silver on blue interior... I replaced the amp which i sourced from an eBay good supplier and connected it. No result ...still not working plus the sugnal lights stop working although the bright & wipers are still workin...kindly advice what to do...thanks and be safe (that is why I was asking what the connector on the the bracket of the amp for...
I had an issue once with the ground for the cluster and some electronics behind the dash getting a bad connection that made some of the lights and gauges quirky, I took all the brown wires off the screw they were on, cleaned everything with a brass brush and reassembled and it solved my gauge issues. You've tested the actuator under the hood, and the wiring in this video and replaced the amp and its still not working? any chance you have LED bulbs in your tail lights?
@@trythistv no LEDs (it's tacky even though Kent suggested).... however it is true that when I pulled out the cluster partially since the kick panel was off already, that is when the turn signal lights stopped working. Will follow your advise. One more thing , the fog light indicator on the light switch which I pulled shows that smallest bulb light I think is there in the car world is missing. do you have any idea where to source it? thanks and be safe.
Hej good video
I have only 10 connections on my early version. Please help.
I will do the repair after part 3
I'm working on editing it, I'm trying hard to make it clear and understandable, the amp is by far the most complicated part, and there is very limited documentation surrounding it, so some things I've been reading on and other things required some trial and error to solve, now I just need to get it together so it all makes sense!
great video .... i noticed that you did not test the actual cruise control switch on the steering column
I didn't get a good angle, when you hear me talking about resume, off, accelerate and decelerate I was pushing the stalk that is on the column to those positions
@@trythistv ....so that in it of itself that the stalk is in good condition...thank you
Exactly, That test proved the switches in the stalk are all good as well as all the wiring all the way to the amp.
@@trythistv ... what about the other connector that is mounted on the bracket of amplifier? where does it connect to and you did not test it? thanks
Yes he did test the stalk in Part 2.
Does anyone know what is the part number for the Cruise Control Amplifier for 1982 240D??
002 545 3232
My number 14 slot is empty so I've no idea what to do
What kind of car do you have? I've suspected that there could be differences in wiring but haven't run across it yet. I made the videos and documents around a 1982 Mercedes 300d, I know some models used slightly different amps, I can try to find out what yours would be if it would be helpful!
@@trythistv thanks for getting back, I just found the information in my documents, according to them, pin 14 is an optional earth which will allow the cruise control to operate at a much slower speed, which to me is just some sort of witchcraft! It's a mercedes 410d...
I've also got 3 hot wires going into pin 1!
👍
I ran your tests with the ignition on, engine running, I got 14v every time, but in phase 2 of the test with ignition off I got the following....
Pin 7 to 10 = 5ohms
Pin 7 to 12 nothing
Pin 10 to 12 nothing
Pin 5 to 12 = 37.4 ohms
Pin 9 to 12 = 2.8k ohms
Pin 9 to 13 = 113 ohms
According to your chart that means my actuator motor is shorted to ground, 113 ohms is supposed to be 0, and the nothing readings are supposed to be infinite and my multimeter reads 1, as though the prongs were not even touching anything. I get a 1 reading both when touching and not touching the pins basically. I've absolutely no idea what that means or where to look next
(mercedes 410d with vdo tempostat)
Update, 1 also means infinite on this particular cheap multimeter! Ignore what I said, although I still don't get why I'm getting the 113 ohms when it should be 0
2nd update... I had 113ohms resistance on 9-13 but the next day it was reading open circuit!
3rd update, I successfully carried out test one with a 12 volt battery, everything works. And in doing so, pin 9 to 13 came back to life but this time it's around 60ohms!
What witchcraft is this??
Please you are literally my only hope in the whole world
So, 9-13 being off from the normal reading is related to the actuator potentiometer, which is how it senses the "throttle position" of sorts. 113 ohms is very high, even 60 with your new test is also very high, Pins 2 and 3 on the actuator itself are the potentiometer, you could test with a multimeter at those pins and move the arm with your hand to see if the ohms sweeps smoothly or if there are dead spots it could indicate the potentiometer parts inside the actuator have worn out, if the readings are good at the actuator pins, then you may have a bad wire between the actuator and amplifier.