need vacuum diagram for 1985 300 td

[jimnichols]

got a great deal here in tennessee on a '85 300 td 200,000 miles great body average interior like the car ok runs well, Been a mechanic on german cars and now work for the railroad. Cruise doesn't work at all I think it is vacuum related, and yes I have checked the vacuum pump and it is supplying a good and steady vacuum power brakes work good as do door locks. Vacuum gauge looks good in the system so........Any help appreciated

[engatwork]

You need to sell me that car and prevent the turmoil that is sure to come if you continue ownership. Welcome aboard.

Non-working cruise does not have anything to do with vacuum. Do a search on cruise amplifier. Get it re-soldered or do it yourself and get back with us. You will enjoy that car.

[jimnichols]

ha there is a thought just sell the stupid car! ( actually it is a great car) just put a blaupunkt BPT660 in it and some speakers to handle the power and it sounds great even if the factory dash speaker covers need to be modified. Mercedes are cool but I am not a rabid fan they are great cars long lived and all but still just a mechanical contrivance very well built and superbly built but still just cars to take me to work.... cruise module ( the one that works the throttle linkage) seems to have only 2 vacuum lines going to it, so I figured it was a diaphram that was busted in it. There is no electrical parts to the " cruise module" for want of the description that I can see so there could be a vacuum prob with the system right??? Jim

Ps I know what the td in 300td stands for unlike many who think it is turbo diesel it really stands for totally docile

[Brian Carlton]

Originally Posted by jimnichols

There is no electrical parts to the " cruise module" for want of the description that I can see so there could be a vacuum prob with the system right??? Jim

The cruise actuator is sitting all the way at the front of the engine toward the driver's side, adjacent to the power steering pump. It's an aluminum box that's about 3.5" square. There is one actuating rod that extends to the throttle linkage. There is one electrical cable that is attached to the unit. There are no vacuum connections.

See photos in post #18 here:

One more cruise control amp repair success story

[jimnichols]

just looked at the cruise actuator and ass-u-me'd it was a vacuum line it was bundled in with the lines that run to the vacuum electric solonoid on the fender well right in front of the cruise actuator plug in DUH lol feel retarted but that is a constant state for me.... learned where all the wires go to the 14 pin connector that comes from the wiper /dip switch on the steering colume though as mine fell apart whilst I was removing it from the bracket that holds the cruise electronic module 14 wires with pins attached free after 21 years of being pent up in that small connecter cant blame them I would be happy too.... lenght had little to do with reinstalling them the slight bend in the wire from being forced to cohabitate with other wire had little to do with the final figure and color ha!!! several were not the same going in as coming out but about 30 min and no right turn signal and no slow wiper ect finally made the right connections and everything is fine again hi beams are suppose to come on when you use the windshield washers right \

resolder connections in cruise electronic module but have a funny feeling that is not going to help with the slight smell of hot electronics that was in the can upon opening will update tommorrow thanks Craig and Brian for the friendly spanking on the difference between multi conector cable and a vacuum line.