Cruise control parts back from GDL... - PeachParts Mercedes-Benz Forum

bjcsc · #1 11-26-2002, 06:05 PM

I read several posts on this board about the very same cruise control problems I was experiencing. I pulled and sent my amp and actuator to GDL for analysis after performing the tests listed on their site, and talking to Peter a few times on the phone. My amp tested poorly (as expected) but actuator tested OK (as expected). I had them open up, inspect, and clean the actuator anyway since it was already there and I didn't want to risk my rebuilt amp to a faulty actuator. Within two days of receipt, both units were back to 100% and on their way back to me. Install planned for tomorrow; will post results in this thread. Total cost about $300 including all the shipping.

David Langsam · #2 11-26-2002, 06:28 PM

I just pulled my amp and actuator and am planning to send it to the very same place. I'm interested in how it works out for you.

David

jbaj007 · #3 11-26-2002, 06:42 PM

bjcsc,
Just curious as to a general price breakdown, since they list the rebuilt amp at $185 exchange?

davidmash · #4 11-26-2002, 07:13 PM

I bought an amp and actuator from them for my Euro 16V and it works great. They have been in for about 3 months now and not even a hic cup.

mcdill · #5 11-26-2002, 08:25 PM

Do they do any models after 1993? My E320's cruise in not working, but it is a 1994 model. But isn't the 300E in 1993 basically the same as mine?

Thanks,
Matt

bjcsc · #6 11-26-2002, 08:32 PM

Quote:

Originally posted by jbaj007
bjcsc,
Just curious as to a general price breakdown, since they list the rebuilt amp at $185 exchange?

Price breakdown was $185 for the rebuilding of my amp (They rebuild your same amp if possible, or if you specify, which I did, otherwise they replace ), $35 for bench testing the actuator, $60 for internal inspection/cleaning of actuator once it passes the bench test and the remainder for shipping both ways.

bjcsc · #7 11-27-2002, 10:16 PM

Finished the install of my returned parts, racing against the ever encroaching darkness. (DST frustrates me to no end - I think they do it backwards) Initial testing put my cruise performance at about 95% in my opinion. (Understand that I am a perfectionist as you read) As far as general operation goes, it is at 100%: sets, accels, decels, turns off as it should. Sticks to the speed you set it at as well. Remaining problem is very slight surging at the set speed, 100-150rpm tops. I can barely feel it, but I feel it - less and less the higher the set speed. I double checked the all the linkage - still very tight from my adjusting for initial diagnosis. I called Peter at GDL to report the progress and get ideas for the next step. He believes, and I agree, that the actuator is probably not at fault, and the amp is certainly not. I believe the remaining 'fine tuning' lies in replacing the speed sensor, which I will do as soon as the dealership is open next. I am confident that the system will be 100% after this next operation.
Going through this cruise diagnostic experience, I have learned a few things that I want to share for the record.

1) The tightness of the linkage at all points is critical to proper cruise operation, as well as proper operation of the speedometer cable. If your speedo needle doesn't move smoothly you better start there. Also check the female connectors at the amplifier and actuator and recrimp them slightly (per GDL). I used a 1.4mm flathead screwdriver (smallest in the common set of minis) and lightly pushed it in between the 'tube' of the connector and the wall of the 'holder', resulting in a slight d-shape on the 'tube'. Be careful not to overdo it! It will take more pressure to plug it back in, but use steady pressure - don't beat on it - and make sure it goes all the way on. Incidentally, I found out from Peter at GDL that some 124 and 126 cars do not have a female #14 amplifier socket. It can cause the same slight surging I am experiencing. It is a ground and making it common to #12 can fix the problem. Call him for details if this applies to you.
2) If after the above, you still have the same symptoms you see on all these posts, do the GDL troubleshooting to the letter except for one thing: testing the speed sensor is difficult as it has to be done with the vehicle in motion with test leads held at two different positions around the driver's feet. Forget about it - just replace it. It's a $30 part, easy to replace, and pulling the instrument cluster out is a PITA - I am dreading doing it again. Go ahead and eliminate the speed sensor from the equation from the get go.
3) The GDL troubleshooting completed, you have now eliminated the speed sensor, switch, linkage, and connections from the problem.
4) If the problem still exists with all the aforementioned items OK, pull your amp and actuator and send them to GDL for testing. For every 1 successful resolder there are who knows how many unsuccessful. Not to mention, there are a limited number of these original boards and once you waste yours-it's gone (and so is your core)
5) Your amp has a 90% chance of being at fault now, but unless you send your actuator in as well, you risk blowing a replacement amp, as it is not possible to determine the exact state of the actuator unless you have the equipment (which costs far more than the testing)
6) Don't open the actuator yourself. There's really nothing you can determine from doing so and there is a tricky spring in there - waste of your time.
7) Pay the extra $60 for the internal inspection on your actuator. Just because it tests well doesn't mean it is A-OK inside, and to hell with going through all this to do it all again (if it fails it will more than likely blow your amp)
8) When your parts get back, you should be at 100%. If I had replaced my speed sensor I would be I'm sure.

Although many of my recommendations cost money (~$300), they are based on my own cost/benefit/time spent/frustration analysis. Yours may be different

I will repost once the new speed sensor is installed and give you another update in this thread. One thing I noticed about all of the cruise control posts is a total lack of followup as to how/if the problems were resolved. You'll hear from me in this same thread until mine is 100%. I sincerely appreciate your collective wealth of knowledge as well as the opportunity to contribute my own experiences. Have a Happy Thanksgiving and see you 'post speed sensor'...

bjcsc · #8 12-03-2002, 06:18 PM

The cruise conquest continues...

After some thought on the matter, I decided that if the speed sensor was not working, the cruise would not work at all or would work at the wrong speed if the sensor was partly working. Thus I amend the above post suggesting replacement of the speed sensor to only doing that if you have no initial cruise function at all. On a whim, I swapped in a cruise amp from a 1985 123 which is a different model number, but compatible with my system per GDL. The system operated smoothly and as I expected my rebuilt amp to operate. It seems that my rebuilt amp is not at 100% as I expected it would be. It is now on its way back to GDL for analysis. I have incurred another $17 in shipping, which miffs me to some degree, and we'll see where it takes me from here. Nobody's perfect, so I'll give them another chance without any hassle. However, my expectations are high for try #2. Amp is scheduled to arrive there Friday and I will post an update as to what they found at that time.

Not to beat the cruise issue into the ground, I just think it may be helpful to someone to have this process start to finish in one post. Till Friday...

David Langsam · #9 12-04-2002, 02:47 AM

bjcsc,

I definitely appreciate your posts. Thanks for the updates.

David

#10 12-04-2002, 01:50 PM

Not for nothing, but shouldn't you include a lubrication of the speedo cable in your elimination strategy? I had an old caddy a while back that had a surging cruise control along with a surging speedo. Both of these problems were caused by a dried up speedo cable. It seems that the cable was binding within its sleeve and giving erratic speed info to the speedo and the speed sensor.

The fix was to unhook the speedo cable from the back of the speedometer (which is also where the speed sensor is), pull the cable out, lube it with some graphite grease, and push the cable back in. After this quick fix everything was smooth as glass and the cruise worked perfectly. Just a thought.

Sounds to me like this has nothing to do with your problem, but I thought it should be included in your troubleshooting rubric. What do I know, I'm still looking for my first Mercedes! An '89-'91 blk/blk 560 SEL to be more specific.

-Josh

bjcsc · #11 12-04-2002, 08:15 PM

I agree with you, however I touched on that in #1. I don't know how successful lubing certain cables might be. If the cable can be separated from the sheath, and then both parts inspected, cleaned, lubed and reassembled, success would be high. I'm not sure how other MB cables are, but my 123 cable does not come out of the sheath. If the cable is binding, it's grinding and unless you can get the resulting abrasive 'metal paste' out, you'll continue to have problems. With the cost of the cable being low, I think if you are going to go to the trouble of removing it at all you should just replace it and be done with it for a long while, if not forever. Nonetheless, if lubing the speedo end of the cable has worked for you (and for others as I have noticed searching and reading several other related posts) then it should be included in this thread; there is no such thing as too much knowledge.

bjcsc · #12 12-06-2002, 08:00 PM

Today I was notified by Peter at GDL that my amplifier is indeed acting sluggish when bench tested. Thus they are rebuiding a new one for me, scheduled to ship Monday. When I receive it, install it, and test it, I will post a final (hopefully) update.

jbaj007 · #13 12-08-2002, 02:12 PM

Did you happen to notice what they had done to the PCB? The likely suspects? component replaced (burned PCB varnish), resolders, trace repairs (jumpers)?

bjcsc · #14 12-09-2002, 10:20 PM

When you get your amp back it is sealed with a tamper-proof foil seal. Breaking the seal voids the warranty. Although I was very curious what they had done, I wasn't curious enough to void the 4-year warranty. Good thing, too, because I had to send it back and I doubt Peter would have taken it back ( and rebuilt me another one at no expense other than shipping) if the seal was broken ( I wouldn't if I was him). My 'new' one shipped today and should arrive Thursday. As promised, I will report after install/testing.

bjcsc · #15 12-12-2002, 08:13 PM

Well, my 2nd rebuilt amp arrived today. After installing it I found it to work exactly as the 1st did; it still has the same surging. I am really at a loss at this point. I was assured that the 2nd amp would be tested in a vehicle and cannot believe that it was as the surging is very noticable. Luckily, I have a 1985 model amp that works, and again with this amp in it works as smooth as glass. The only thing is, this amp is from a salvage yard and I did not want to depend on it for my upcoming 2000+ mile trip over Christmas. I am quickly running out of time. If I did not have a working amp to compare with, I think I would probably be replacing a lot of good parts (scary). At this point I would like some suggestions as to my next course of action in this matter.

I was not able to get Peter on the phone, but will definitely be calling him tomorrow. I am very, very disappointed...