i just purchased an '87 TDT. it has been well maintained for the most part, but the owner did something stupid right before we picked up the car.

when we inspected the car, he mentioned that it needed a new relay for the A/C aux fan, which he would put in before we picked it up. he described that the fan would not come on at idle and therefore the A/C would stop working at idle, then start again when underway. no problem, i thought. he said he had the part and it just needed to be installed. i have since been doing some digging here on this forum and found that this is a common problem, and not always so simple to repair...

so, before we picked up the car the seller (or his hack mechanic) butchered the wiring harness, installing a 4-pole relay into the circuit that seems to make the aux fan run constantly. it was so amatuerish how it was done, i am tempted to ask for my money back on the purchase! the car is very clean and shows no signs of hack wrenching anywhere else. he drilled a hole in the left side of the fusebox, then soldered a wire to the 'D' fuse terminal, cut the fan harness and ran a wire into another harness which runs over the fuel filter then disappears. this disappearing wire is the trigger for the relay. grrrr, i was so mad when i found this hack, and this after the seller went on and on about how he had meticulously maintained the car and always done everything "right". sure, you did, mister. and he expected me NOT to notice the cut wires, dangling VW relay complete with duct tape ball on the wires and zip ties in the engine bay? holes drilled into the fuse box? this work was definitely done between when we placed our deposit on the car and when we picked it up a few days later. there were no loose wires in the engine bay the day i looked at the car the first time. grrrr, i say, oy, i was sooo mad. our beautiful new car

i have only had the car for 2 days, and my wife is today taking it back to the seller to have this shoddy work rectified or at least undone, but in the meantime i want to research how to undo the hacking and fix the A/C properly. searching here it seems that the switch on the receiver/dryer may be at fault. it looks like replacing this switch on an 87 TDT will require opening the system, is this correct?

last newb question, what is the best source for a good manual? i prefer paper, but have not found much available. the manuals from fastlane look promising but are awfully expensive. i am feeling completely lost without a good manual, i have been wrencing on cars for all my adult life, mostly VW and Volvo, this is the first Mercedes-Benz i have owned. i have dozens of repair manuals and always look to them first before picking up my tools, but here i am stuck and needing help until i get a manual for the new beast.

thanks,

scott lyons

doesnt offer a 300 e handbook for that era but they do offer a 190 and i think you will find most things are the same or very similar on the 190 .
i would think you have the basis to demand your money back. did you pay a price indicative of a working ac system? if so that is a major expense and will reflect on the price very negatively if it doesnt work.

i would be pissed too!

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If you are just looking for wiring diagrams, Autozones' Alldata might be a consideration. Check under commercial. It is less than the CD's ($40) but are not very good for anything else. Haynes makes a manual, Mercedes-Benz Diesel, for the W123 series that covers a little more maintenance. Believe it or not, I found very good wiring diagrams at the city library and photo copied a few there.

I can understand you being peeved. Especially since he did the hack job after you had already placed a deposit. You may be able to splice the original wiring to near new and epoxy the hole in the fuse housing, however. Like you, I am very leery when I see hack work done.

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Sam

84 300SD 350K+ miles ( Blue Belle )

thanks for the replies. peeved doesn't come close to describing how i feel. i have bought and driven used cars all my life and never had a negative experience up to now, but this guy takes the cake. my wife too the car back to him today and he flat out refused to do anything. jerk. the worst of it is that he is a friend of a friend.

now, on to fixing the problem.

the fan now runs constantly since the new wiring bodge has created a circuit that seems to get a signal from the compressor, so whenever the compressor is running, so is the fan. fine, at least we have A/C, but we also have a bunch of bodged wires in the engine bay, a constant 10A draw, and a hack job in my nice new car. i hate hack jobs.

i see there is an "A/C Temp Switch at Receiver/Dryer". i am referring to the worldpac parts catalog. from what i have found searching here, the A/C temp switch is often the culprit when the aux fan fails to turn on at hot idle. how can i test it? also, is there a resistor attached to the fan? i have seen mention of the resistor going open, but i don't know what to look for to find the resistor.

until i get myself a decent manual of some sort, i am at your mercy, mercedes gurus.

speaking again of manuals, are the CD versions any good, or not applicable to the '87 TDT model?

thanks,

scott lyons