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View Full Version : Which Relay is Fuel Pump Relay (PIC)



Jim525it
03-18-2006, 11:00 AM
Could someone please tell me which relay is for the fuel pump?
Its a 94 525it.

Orange, white or blue?

Thanks,
Jim

p.s. I think I attached a picture....

ArtemLepilov
03-18-2006, 11:45 AM
Im not sure - I dont have my bentley with me at the moment, but if you are just looking to stop the fuel delivery you can pull the fuel pump fuse.

-Artem

Jim525it
03-18-2006, 12:49 PM
Im not sure - I dont have my bentley with me at the moment, but if you are just looking to stop the fuel delivery you can pull the fuel pump fuse.

-Artem

Thanks, but no. I'm trying to figure out why my car won't start.
Jim

Bill R.
03-18-2006, 01:29 PM
the direction from your photo but it looks like the blue one is the closest to the engine




Could someone please tell me which relay is for the fuel pump?
Its a 94 525it.

Orange, white or blue?

Thanks,
Jim

p.s. I think I attached a picture....

Javier
03-18-2006, 02:12 PM
Javier

Jim525it
03-18-2006, 04:27 PM
Javier

Yep, its the blue one. Thanks!

Unforn, it checks good and my pump is still not pumping. When the relay is jumped (pin 30-87) I get a 11.7v drop across accross fuse #23 and a similar drop at the pins of the pump assembly. But the pump does not pump.

The real kicker is that its a BRAND NEW PUMP. Maybe I'm just unlucky and I got a bad one...uggh. I don't want to fork another $250 to test that theory. Hopefully the suppler will replace it. I kinda doubt it since I have already installed it, but I will try on Monday.

Jim

Javier
03-18-2006, 05:08 PM
I get a 11.7v drop across accross fuse #23

means that voltage from fuse pin 1 to fuse pin 2 is 11.7 volts = open (fused) fuse, and I guess this is not what you meant. If you get voltage at the fuse (any pin as measured to ground), and at the pump connector as measured between pump connector pins; and pump still does not run, it's probably damaged.

The real kicker is that its a BRAND NEW PUMP. Maybe I'm just unlucky and I got a bad one...uggh.

I don't know the whole history, but may be there is something else here, dirty connector, bad wires from connector to pump, wrongly connected, may be even your old pump is not bad.

Javier

Jim525it
03-18-2006, 05:27 PM
I fixed the problem.

When I got the new pump it had a different wiring connector. It included a kit to attach the new connector to the pump sender housing (OK, you smart people can already guess how I messed up). Changing the connector involves cutting the two wires to the old pump, crimping the wires to the new connector and then pluging the new connector into the new pump.

Long story short the posts on the two pumps although located in similar places have opposite polarity. So in addition to changing connectors you need to reverse the wires as well.

I tested by removing the pump housing connector, reversing the inputs via a coulpe of jumper cables and the pump jumped into action and the car runs!
(I primed the fuel lines by attaching a spare batter directly to the pump and letting it run until I heard the return line spash fuel into the tank)

Now I need to remove the pump and swap the wires at the new connector.

When I get the old pump out I will take pictures which should make my explanation much clearer.

I am mad at myself, I should know better, but I am also mad at the instructions which came with the new pump. They are misleading.

Thanks for the help. I should be full operational again tomorrow!!!!

Jim

Javier
03-19-2006, 08:43 AM
Javier