Fuel Pump Relay Location on 500SEC Euro? - PeachParts Mercedes-Benz Forum

#1 03-24-2007, 07:41 PM

Hello everyone,

I left my 500SEC in the garage for a couple days this winter when it was very cold (below 0) here in Wisconsin, as I usually do in winter, but this winter we didn't get much snow early on so I was driving it for a little bit while my van was in the shop. When I went out to start it after the weekend, it wouldn't go. So I figured gas line freeze, which is common out here, and forgot about it for the winter, seeing my van was fixed later that day.

Now that spring has rolled around I wanted to take the car for a spin and found that it still won't start. After some checking I realized it's not getting fuel, and it doesn't sound like the fuel pumps are kicking in. I had this problem with my old '86 560SEL and found a bad solder in the fuel pump relay to be one of the issues. So I thought this would be a good place to start looking, BUT I CAN'T FIND the fuel pump relay. In the 560SEL it was pretty much right next to the fuse box, but not in this SEC. I checked the Chilton manual and it doesn't show the location of the relay. Does anyone know where to find the fuel pump relay? Please note the car is a 1982 500SEC AMG European model, which seems to make good service information (or any information) hard to come by. Or does anyone have any advice on what else to check for to diagnose the problem, assuming both fuel pumps are good?

Any help would be greatly appreciated, as I'm just itchin' to get out of the minivan and into the AMG.

Thanks,
Dylan

jhodg5ck · #2 03-25-2007, 10:07 AM

It's hiding in the fuse box

If you need a new one let me know..they euro Gen I FPR's are different then the Euro.

Have fun getting her back on the road!

Jonathan

#3 03-25-2007, 03:25 PM

Thanks for the help Jonathan, it is very much appreciated. I thought that relay was the same as (or similar to) the fuel pump relay, but didn't think it was the fuel pump relay. For some reason I thought I recalled 2 of them in my 560SEL, one in the fuse box and one outside of it, (the one outside of the box being the FPR and the one inside being the kickdown, although my memory of it is definitely not vivid) so I passed it off and started to hunt for it's twin. I'm going to check it out later on this afternoon and I'll be back on to post the results of my findings. Thanks again.

Dylan

jhodg5ck · #4 03-25-2007, 05:00 PM

NP. The later cars (you 560) have both relays behind the bulk head/in the middle of the car. The 500's have the one Klima relay external to the fuse box w/ the FPR hiding inside.

Jumper pins (in the receptacle for the FPR) 7&8 w/ a suitable piece of wire and that will fire up your fuel pumps if everything else is kosher.

Any pics of your AMG/SEC?? I'm a big fan myself;-)

Jonathan

#5 03-25-2007, 09:51 PM

Thanks again for the extra info Jonathan. You're proving to be very helpful, and again I appreciate it tremendously.

I popped the relay, opened it and checked for bad solders, it looks brand new. I also tried to jump pins 7 and 8 with a nice solid piece of copper that fit real snug, but apparently the relay is good.

Although it showed a brief sign of wanting to start, it did that as well when I popped the relay back in. And popping off the main fuel intake to the engine proved I'm still not getting gas. When I pour a little gas into the air cleaner, the car pops off and runs like a gem, until the gas is used up and then it quits. I guess my next course of action is to pop the fuel line in front of the fuel filter to see if it's actually pumping fuel out of the tank. Then I would know I just have a blocked or pinched fuel line.

If you have any ideas on what I might want to check next, please keep the advice coming. Again I appreciate it very much.

Thanks again,
Dylan

p.s. I'll get some good pictures taken of the car this week and post them in my gallery. But please note the car is in need of a little body work and restoration, which I guess could be expected from a 25 year old machine. (Though it still looks super nice from 30 feet =). It's sort of my project car, but it runs so good I wouldn't hesitate to drive it to Georgia......if it would start.

jhodg5ck · #6 03-25-2007, 10:44 PM

can you hear the pump running?? W/ the wire in there you should have a Definite audible hum from the pump.

If you do not hear the pump running check your positive battery terminal, make sure it and the two 10 gauge wires feeding off of it are snug.

If the pump is humming and you are not getting any fuel I'd worry that you either have a clogged line somewhere in the system but we'll tackle that next.

Also, if you are working on the car and want to chat in real time feel free to give a ring, 404 805 1357.

On a side note, how far is GB from Madison? I spent some time up there and Really enjoyed it.

Jonathan