What is a Fuel Pump Relay?

What does it do? I'm not an electrician or car expert, so just need a
simple description of it.

Thanks!

 

What does it do? I'm not an electrician or car expert, so just need a

I'm not exactly sure, but it probably protects and/or directs the circuitry
that goes to the fuel pump. I believe mine is working intermittenly. The car
runs fine when it works and dies when it doesn't.

 

The fuel pump relay supplies the main fuel pump with electrical power all
the time the engine is running.

If the engine stalled the supply to the fuel pump would be cut some 2 to 3
seconds later.
Fuel after the main fuel pump is at a high pressure, and really ought not be
sprayed around too much in the event of a crash.

Steve

 

It's an electrically actuated switch, which lets you use a lower power
circuit (from the ignition switch) to control power to a high current
device, like a fuel pump. They come in a variety of shapes, depending
upon what year your car is. In the case of my '72 145, it's a galvanized
metal box mounted on the right side of the engine compartment.

You're welcome.


Gary

 

The fuel pump relay on my 240 series lives on the drivers side
footwell area. It's job is to turn the fuel pump on when it is
supposed to be on, e.g. when the engine is running or trying to run
and to not spray fuel all over the place if the engine is not running,
for example in an accident. This is done with some eltrical contacts
and magnetic coils. Sometimes the solder joins fail and relays don't
work very well or at all. Sometimes they work when you tap them a
little. You can bypass your relay by jumping (on a 240) fues number 5
and 7 I THINK--check this with a google search first, or just check to
see what fuse 5 and 7 does. No starts in volvos can be either of the
two fuel pumps or the relays, this is an easy one to check with a
jumper and a test light.

 

Thanks for all your help. Mine was replaced on a 740 and the mechanic just
left the failed old relay for my reference. It's just a small rectangular
box which says "Made in Germany". Hope the new one works well and won't
stall my car...

I have another question later on regarding another part that was added on
last time my car stalled. Didn't get a chance to ask my mechanic, but I
think you guys will have a better description anyway. Will post the
question as soon as I find my invoice.