88 300e a/c wiring diagram?
Thread Starter
Newbie
Joined: Jun 2003
Posts: 13
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From: Phoenix
Mercedes-Benz 300e
88 300e a/c wiring diagram?
HI. How lucky am I to have found this site! Any insights would be appreciated. Bought an 88 300e about 6 months ago from a friend of a friend, third owner, 160m miles, very well taken care of so felt comfortable taking on the challenge. Anyway, replaced the blower moter because it would work only sometimes like when I drove over a railroad track- but then would make a noise anyway (like a bad compressor belt). Now, the blower works great but the actual cooling seems to turn itself off when it gets too hot outside. I can sometimes reset the a/c if I turn off the car and restart...for a while anyway. The cars temp goes up too. I'm in Phoenix. Arizona. It's 106 today.
I think my mechanic can work on this car; he used to take care of my 'Z' but we think we need a wiring diagram unless someone can relate a similar problem? He has my car right now, so if you come up with anything, please let me know. Thank you!
I think my mechanic can work on this car; he used to take care of my 'Z' but we think we need a wiring diagram unless someone can relate a similar problem? He has my car right now, so if you come up with anything, please let me know. Thank you!
Senior Member
Joined: Jun 2003
Posts: 302
Likes: 1
From: Salem, OR
08 Lexus GS350 AWD. 08 Lexus RX350 AWD - wife's. 94 MBZ E320 - still have it.
I had similar problems on an '86 300E I used to own. In my case it was bad ignition switch, the electrical part of it (abot $20 part). That could explain why you can re-start the AC after re-starting the engine.
A year or so later, I had to replace the climate control module (heater and AC push-button unit). That part was about $200 for a rebuilt unit, and it was fairly easy to do.
Good luck
A year or so later, I had to replace the climate control module (heater and AC push-button unit). That part was about $200 for a rebuilt unit, and it was fairly easy to do.
Good luck
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,005
Likes: 33
From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
I doubt its a electrical problem. I had the same appearence in my '90 260E. Some cool under fair summer temp. but fading with increasing outside temp. Normally the A/C looses refrigerant over time. The system contains not enough R12 to built up the pressure for higher outside temp. If the pressure is not reaching a certain threshold the extra cooling fans for the condensor, in front of the radiator, wont switch on and the motor temp. increases also.
If you A/C still operates on R12 you need to convert to R134, since R12 is not in market anymore. Dont try the "replacements" only trouble!!!!. Convert the A/C to R134 (standard in all new cars) I had this done at the MB shop. You need to drain and replace the compressor oil, a new dryer bottle, 2 new pressure switches and a complete refill of R134. They charged me $ 350 all together. And I can tell you my car COOOOL now, as on day 1.
If you A/C still operates on R12 you need to convert to R134, since R12 is not in market anymore. Dont try the "replacements" only trouble!!!!. Convert the A/C to R134 (standard in all new cars) I had this done at the MB shop. You need to drain and replace the compressor oil, a new dryer bottle, 2 new pressure switches and a complete refill of R134. They charged me $ 350 all together. And I can tell you my car COOOOL now, as on day 1.
Thread Starter
Newbie
Joined: Jun 2003
Posts: 13
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From: Phoenix
Mercedes-Benz 300e
Thank you both for getting back to me, I have since replaced some other things since reading your response-the head has been reconditioned which they said would solve the problem and on my way home it stopped working. I'll check into the two things you guys recommended today.
Newbie
Joined: Jun 2003
Posts: 15
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From: Houston
92 400E
Tamara...
Go to ebay ...you will find people selling the MB maintenance discs for about 30 bucks ...well worth the investment. It contains wiring diagrams and mm procedures for just about everything. make sure you specifically buy the ones for the 124 series. If you need a specific diagram...let me know so I can search for it among my dusted binders that my wife is urging me to throw away.
Go to ebay ...you will find people selling the MB maintenance discs for about 30 bucks ...well worth the investment. It contains wiring diagrams and mm procedures for just about everything. make sure you specifically buy the ones for the 124 series. If you need a specific diagram...let me know so I can search for it among my dusted binders that my wife is urging me to throw away.
Thanks maxjet! I'll definitely buy the discs on ebay! Yeah!
