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I have been all over both sides of this car and can not find the fuel pump relay. I have the MAS and the OVP removed but can not find the relay. Most information points to it being behind the battery but we can not find where it might be. We have also heard that it could possibly be near the fuse box, not finding it there either. I am pulling my hair out. Can anyone offer assistance here on this issue?
 

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Interesting response-

Which search engine are you using, google has not offered me any other location than the two options listed. I have seen pictures and diagrams and searched this over and under and still can not find the part that I find pictures of. Apparently others have this same problem with locating these. Thanks for your response.
 

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1993 190E 2.6, 1990 300SEL, 1992 300SE, 1992 400E, 1987 190E 2.6 murdered by my brother.
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I am looking at the Official Mercedes M103 engine manual right now. It shows that its to the left of the OVP relay in the older 1989 model. A black rectangular box numbered #
001 545 90 05 and labeled 12 V. It is right behind the battery. The black box is the relay dude. I have it in my 1993 2.6. So you calling me a liar?
 

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Discussion Starter #8
Not calling anyone a liar, just trying to figure out why some people including myself are having a time of locating this part.

I went to the part store and they do sell a fuel pump relay for this car. When we bought the car it was already being worked on by the owner for this fuel issue. I swear it is as if he has taken the entire wiring harness out!

I am hoping that someone else who has had this problem will respond to my request for help and solve this mystery.
 

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Discussion Starter #9
The later models did not have a separate fuel pump relay. This function was combined along with other functions into the MAS relay.
Later models? I have a 1992 Mercedes 190E with a 2.6. By not finding a separate fuel pump relay located behind the battery next to the OVP as described on some models, I must agree with you that it seems to be combined into the MAS relay. Can this be verified via the MAS part number? My MAS relay part number is 011 545 79 32. Thank you so very much for your help.
 

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W-1-2-3 Go!
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My uncle's 91 2.6 has a MAS relay. Yours should too. And if you have the MAS relay, the fuel pump relay function goes with the MAS relay functions.

I don't know which pins to jump when you have a MAS relay to get the fuel pump to work (as part of the diagnosis, or as part of setting the fuel pressure in the fuel distributor).

The FSM calls for jumping two pins on the fuel pump relay socket on the older models to do the same thing (and to test whether the fuel pump relay is bad or not). When the FPR went bad on my 2.6 we jumped the two pins and the fuel pump worked, confirming that the relay was bad.
 

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Discussion Starter #11
My uncle's 91 2.6 has a MAS relay. Yours should too. And if you have the MAS relay, the fuel pump relay function goes with the MAS relay functions.

I don't know which pins to jump when you have a MAS relay to get the fuel pump to work (as part of the diagnosis, or as part of setting the fuel pressure in the fuel distributor).

The FSM calls for jumping two pins on the fuel pump relay socket on the older models to do the same thing (and to test whether the fuel pump relay is bad or not). When the FPR went bad on my 2.6 we jumped the two pins and the fuel pump worked, confirming that the relay was bad.
Acknowledging the fact that my 92 mercedes 190E with a 2.6 (much like your uncles 91 2.6) has a MAS relay which houses the fuel pump relay function. My question to you kind sir, is if I were looking to buy a used MAS for my car, must the MAS part # 011 545 79 32 match exactly with the replacement part? In other words, do the mercedes that have a fuel pump relay (much like your older model 2.6) even have a MAS? If so, is it a different part number? I ask these above questions to insure that I order and receive the same replacement part as mine when ordering a MAS. Thank you for your wisdom.
 

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Acknowledging the fact that my 92 mercedes 190E with a 2.6 (much like your uncles 91 2.6) has a MAS relay which houses the fuel pump relay function. My question to you kind sir, is if I were looking to buy a used MAS for my car, must the MAS part # 011 545 79 32 match exactly with the replacement part? In other words, do the mercedes that have a fuel pump relay (much like your older model 2.6) even have a MAS? If so, is it a different part number? I ask these above questions to insure that I order and receive the same replacement part as mine when ordering a MAS. Thank you for your wisdom.
My 89 190E does not have a MAS control unit. It has its own separate fuel pump relay. Technically, the MAS relay is a fuel pump relay that has other functions.

http://www.benzworld.org/forums/w201-190-class/1518806-where-fuel-pump-relay-1992-2-a.html

http://www.benzworld.org/forums/w201-190-class/1369238-strange-box.html

http://www.benzworld.org/forums/w201-190-class/1395736-fpr-mas-my-brain-hurts.html
 

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Interesting response-

Which search engine are you using, google has not offered me any other location than the two options listed. I have seen pictures and diagrams and searched this over and under and still can not find the part that I find pictures of. Apparently others have this same problem with locating these. Thanks for your response.

either one
 

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1991 190e 2.6 automatic
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i doubt mas relays go bad. I got a 91 2.6 and it uses the mas relay too. the only fuel related problems i had in 10 years was just a bad OVP relay.
 
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