Hi All,
I have currently purchased a 87 model 300 turbo diesel black/grey 180k , I'm glad to have found this forum. I've read through a lot of posts and there is a wealth of knowledge. My problem is the cruise control will not engage. the encrease speed part of it works, thats it. I remember reading a post about the amplifier. Does anyone have any suggestions. Also looking for a source for manuals......
Thanks... New Owner

Dave:

Ebay is a good place to look for manuals. I think the W124 manual set is out of print, but I may be wrong. The CD is available from FastLane, and I can recommend that. Not as nice as a book, but better than fishing!

If the cc won't set, the amplifier is bad. Check your stop lamps for good contact, too, as the amplifier ground is via the stop light filaments. Sometimes replacing the bulbs helps.

Also, check the linkage for binding -- the cc servo is the big box behind the injection pump.

Most usually partial function means the amplifier is bad. Search MercedesShop -- there are several suppliers of rebuilt amplifiers, and this should cure the problem. Also a good deal of info on diagnosis, too.

Bet you love that 87 300D, though, cc or not!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

PSFred,

Thanks for the response. I'll check out the linkage and replace the bulbs. Could be a cheap fix. And yes, I really enjoy the turbo diesel....... Thats why I need the cc.....The car doesn't like going less than 75 on the Highway... I see a ticket coming soon......I'll check ebay on the manuals..



David.

David:

I've had to "relearn" driving a diesel when in the 300D -- if you put your foot in it like I do on the other cars, it flys. It's a trip to blast away at stop lights, but eats up way too much fuel. I have to drive mine almost like a gasoline car -- light throttle and let it run up rather than open up about halfway, then back off. Tends to run away uphill, too, a novel experience in a diesel for me -- the other two don't have the horsepower for that.

With the CC working these things just eat up highway miles -- I managed the trip from Hollywood Florida to Macon, Georgia in 8.5 hrs! Never exceeded 80 mph, but without the CC definitely would have!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

About that CC amplifier...my CC wasn't working at all when I first purchased my 240D a few months ago. Then I found an article that told how to sometimes salvage one by soldering all the joints in the amplifier. All you do is heat the joint enough for it to melt then let it re-set. It worked for about a month, then started acting just like you describe yours. Took it out, did it again and now it's working great again. (Apparently the connections can lose contact with age and vibration.)

By the way, psfred, I was down at the pull-a-part yard in E'ville last week while visiting my mother at Deaconess. What a great place! Got some good parts I needed for the 240D.

psfred,

I just saw that you have a Volvo turbodiesel. Our '91 Caravan waylayed Bambi's next-of-kin just before Christmas, so I'm looking for a replacement vehicle. One is a '92 Volvo 740 Turbo wagon with 180K mi. It has few records (the owner apparently threw them away thinking they were unimportant clutter when cleaning out the glove box--and I believe that he did). In your opinion, what's a decent price to pay for it?

I appreciate any comments.

Bill:

Oh no, someone found my secret stash of MB parts! Help!

Was that the brown 230 at Liberty or do they have some more there? I've not been for a while, no time. Great place, by the way -- cars well separated, up on WELDED rims, everything nicely accessable, good folks.

Don't bother with Glissons -- too dangerous. I've had cars move while I was in them, won't go back unless I can't find what I want elsewhere.

I'd say $5000 to $8000 for the 92 740 Turbo -- nice car, my sister has one that I put a head on last summer (radiator nipple broke off, plastic rad disease). Less, of course, if it has any problems.

If you get one, check the upper radiator hose nipple regularly -- green antifreeze causes it to fail. Usually results in the need for a new head, which isn't too bad, but a pain in the butt if you need the car.

No brass and copper replacement rad, or I would have put one in. The replacement is just at $300, ditto for the head.

The turbo model has plenty of power, and my brother in law said it got 30 mpg in good shape -- got 24 or so in it after if fixed the head.

Turbo will go if not cooled off after highway runs before shutoff (brother in law replaced that, too!).

Volvo trannys tend loose first gear, so check for funny shifts -- replacement is usually the best option.

Wiring is a problem, and will drive you nuts if it starts to go. Not a problem on Sis's so far.

More info on a website called swedishbricks.com

Other wise a very nice car.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

Yep, I got a rim from the 230, but there's also a yellow 240D that's pretty well stripped. Has several parts I needed, though.

I appreciate the advice on the Volvo. I believe I can get it for about $3000, so I'm definitely considering it. It will be the car for my wife and kids, although I'm sure I'd have to have an occasional blast about the countryside in it.

However since yesterday I'm in a bit of a quandry, for I also found a local '85 300D with 177K mi for $1000. I have yet to look at it, but it must be decent, because the owner is currently driving it back from a trip to Florida. Likewise, it too would be in the possession of the wife and kids.

I believe these are much better options than any minivan I could find in the $3000 price range.

Good to "talk" with you and have a great day!

Bill:

Was there a driver's side mirror on the 240D? We need one.

What a Hobson's choice -- between the two very longest lived and safest cars from the 80's! Choose well, you will be living with it for a long time! The Volvo's tend to go as long as the MBs with little or no engine work, and rust isn't an issue on the Volvo, in general.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Bill,
So, You said that I can just remove the amplifier, disassemble it and check the solder joints. That doesn't sound too bad. How hard is it to remove the amp?

Thanks David

If you decide to do the re-solder job, replace the electrolytic capacitor while in there. I have read that they won't last but about twelve years. Cost about $1 at Radio Shack, pay attention to the +- and go back the same way.

Harry
86 300 SDL

Here's where I found the information for my repair:

http://mbca.org/MBCA_Troubleshooting_cruise_cont.htm

I also read elsewhere that it's a good idea to tape of the PC board into sections so you can keep track of what you have & haven't done.

The first time I did it took about 1 1/2 hrs. all together. A few days ago I did it again in about 45 minutes.

Good luck!

Peter,

I can't recall whether it had a mirror or not. The 300D turned out to be a 300CD (so much for a 4 door ). This fellow also offered me an '81 240D with manual tranny for parts for $100. He said there's a knock in the motor. It's by Salem, IL if you'd be interested.

Have a good day.

Bill,PsFred,and Harry

I appreciate all your advice on repairs to the cc.. I checked the bulbs to make sure they were oem.,Removed the amp and inspected all the joints. They all looked ok. I read the article about cc repairs and it sounded like I should resolder the joints even if they look ok. The only problem I saw, or should say smelled was a burnt circuit board smell although I could not see any evidence of burned resistors. I would hate to replace the amp. just to find out that something else is the culprit......

Thanks

Stuck servo or binding linkage can overload the amp and burn it -- MB doesn't seem to have any idea of using current limited circuits for servos.....!

The is an address for a website of a company that rebuilts servos, amps, etc -- you will have to search for it, since I'm getting early Altzheimers and cannot remember it. They give very good advice about this system.

At the very least, do NOT put a new or rebuilt amp in until you have verified the current draw on the servo! They have been known to fry the MB diagnostic machine when bad!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!