PeachParts Mercedes-Benz Forum

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/)
-   Tech Help (http://www.peachparts.com/shopforum/tech-help/)
-   -   Fuel Pump Relay 420 SEL Question (http://www.peachparts.com/shopforum/tech-help/160359-fuel-pump-relay-420-sel-question.html)

mooky9669 08-02-2006 09:09 PM

Fuel Pump Relay 420 SEL Question
 
I was wondering where the Fuel Pump Relay was for the 450 SEL???? My dad's car sounds like it was to run and it does for a while than dies. It's not the fuel filter because it was fairly new. Might be the fuel pump and read you have to have 2. Thought it might be the fuel pump relay, but can't locate it.

milterino 08-03-2006 12:12 AM

Relay
 
On my 76 450 SEL in the fuse box there are 3 relays fastened to the side of the fuse box. If you are standing on the drivers side looking down at the fuse box these relays project twords you. The one on the left or to the front of the car is the window relay, the one to the right is the start relay and the one in the middle slightly lower than the other two is the fuel pump relay. Milt.

mooky9669 08-03-2006 08:33 AM

Thanks for the info...actually it's a 420 SEL..typed 450 by mistake. Think we found the fuel pump relay. Another quick question....This model has 2 fuel pumps and I was wondering, do they go out at the same time???

Whiskeydan 08-03-2006 12:37 PM

Quote:

Originally Posted by mooky9669
Thanks for the info...actually it's a 420 SEL..typed 450 by mistake. Think we found the fuel pump relay. Another quick question....This model has 2 fuel pumps and I was wondering, do they go out at the same time???

They should have roughly the same wear.

Is one getting warmer than the other? Maybe that one is at fault. Can you measure the current draw of each pump? I would think the bad one will be drawing a lot more current. However, a true test would be to swap there positions and re-test.

mooky9669 08-03-2006 08:43 PM

I could do all that if I can get it to the mechanic. Tried to start it up again and nothing. Sounds the same like it wants to start than nothing. Gonna see what we can to tomorrow about getting it to the station. Thanks again for the help. Also, how do you tell if the fuel pump relay is causing this?

Gilly 08-03-2006 09:32 PM

You can jump 2 pins in the socket the relay plugs in to to bypass the relay temporarily to see if the pumps will run.
The engine will run on just one pump, in case you were wondering.
When you jump the relay, be sure to remove the jumper when you shut the engine off (just to save your battery, the fuel system will be fine).
The fuel relay is NOT the one that says "Klima" on it, it's the one that lists the rpm and also the amount of cylinders (8 zyl).
IIRC the 2 pins correspond with "30" and "87" when you look at the pin-out diagram on top of the relay. They are about in the middle of the 2 rows and directly across from each other.
Gilly

macdoe 03-28-2010 02:59 PM

Hello, where is the location where you jump these two pins to get the fuel pump to work? I have no idea where any of these fuel system components are? Thanks.

hookedon210s 03-31-2010 09:14 PM

Remove the fuel pump relay and jumper female slots 7 and 8 in the plug from where you removed the relay. CAUTION: Power will go the fuel pumps even with the key turned off so remove the jumper when you are finished testing. Mark


All times are GMT -4. The time now is 04:57 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website