1972 Mercedes 280 SEL 4.5 Will Not Start

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Feb 16, 2015 | 07:51 PM
  #1  
This car is in beautiful original condition and still in the original purchaser's family. Though a bit dusty at the moment, it is well maintained but has sat in storage for a while. It has been started and moved regularly but finally the brakes started sticking so the callipers and master were rebuilt and all hoses replaced, then the system was flushed.

It was not started while the brake work was being done and now it will not start at all. Even before it was necessary to pump the pedal to start it but at the time I didn't realize that it had an electric fuel pump and fuel injection so pumping should have never been needed. With this current problem, I checked to see if the pump is getting power and it is not.

The fuse is good but there seems to be some confusion where the pump relay is located but I understand that it near the right headlight and below two round relays. I can see the round ones but not any square or rectangular ones. One source says that it is the relay on the wheel well to the rear of the battery but that appears to be the starter relay.

Any ideas would be greatly appreciated! Does anyone have a wiring diagram?

Don
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Jul 8, 2015 | 03:29 PM
  #2  
hello, good morning. off-topic question, but I was wondering, does the key that you are using in the ignition also open the trunk? I cant find a person or dealer on this planet that seems to know. my key wont open trunk and i dont know if its a valet key or ignition/door key. thanks so much
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Jul 8, 2015 | 10:41 PM
  #3  
fuel pump relay location
I realize this is in response to an old post, but someone else might need this info. The fuel pump relay is on the rear of the control unit mounting panel. Remove the panel to access. At top, there are two round relays. Below is the voltage regulator and two rectangle relays. The lower one is the fuel pump relay.
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Jul 8, 2015 | 10:48 PM
  #4  
valet key
The valet key will operate the door and ignition, but not the trunk or glove box.
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