1986 560sl, where is the fuel pump relay?
 

How bout' the check valve? Doing the pumps and filter, might as well check the whole circuit while I'm making a mess of things.

Thanks.

JBoggs

Not sure what check valves you mean.
if you are talking about fuel return check valve, they are on the fuel pump itself.
if you are replacing the fuel pumps,than you are replacing the check valves.good luck Harald

fuel pump relay
 

It is behind the glove box, there are three relays there that look similar, the one on the right is the climate control relay, then there are two on the left, the one in front is the idle speed control relay and finally the one in the back is the fuel pump relay, pull the clips on the glove box insert and you will find it there.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=107048%5F14F&M=117%2E967&GA=722%2E313&L=765%2E707&CT=F&cat=14F&SID=54&SGR=120&SGN =06

I just looked it up at work.
It is behind the behind the GLOVE box.
The bigger black one is the idle speed speed control unit and on the right of it is a silver fuel pump relay.

Bigger? all three are the same size

well thanks Carson for your nice reply, but I did say black,and no they should not be all the same size

See the link picture, one is the climate control relay and the other is the fuel pump relay.
I couldn't find a picture of the idle control relay, but for the 560SL it looks the same.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=107048%5F14F&M=117%2E967&GA=722%2E313&L=765%2E707&CT=F&cat=14F&SID=54&SGR=120&SGN =06

Hi Carson ,yes you are correct that the first one is the fuel pump and the second is for the a/c, but those are not for the 86 560SL.
I looked it up on AllData and they are saying that the fuel pump relay is a smaller relay and this one is silver.
You are correct that that is the normal relay for the 126 and 124.
But I think the 107 has a different relay.
I wish I could post the pix from AllData so you could see

Your AllData is mistaken, Mercedes hasn't used the silver cube relay to control the fuel pump for many years on the 107, the information I have is from current factory Mercedes information, and from personal experience.
The very week this was originally posted I had to troubleshoot a fuel supply issue, I had to bridge the fuel pump relay at pins 7 and 8 in order to bypass the relay and measure fuel pump amp draw.
I assure you that for the 1986 560SL the relay is the larger black relay which is Mercedes part number 003-545-01-05