Hey guys! Thanks in advanced.

Replaced both fuel pumps on the wagon and she is runnuing pretty well. I noticed the main pump sounded like it was working too hard and determined the prepump (in tank) isnt running.

I removed fuse 5 and jumped it to fuse 7. The left side of 5 runs the main, also received a “spark” on my paper clip. When I test the right side of the fuse to jump the pre pump I hear nothing running nor is there a slight spark on my paper clip. Does this mean there is no power to the pump? Shouldn’t I at least get the spark when I make the connection in the fuse box?

Just wondering if i need to start tracing wires or go directly to the pre pump.

The relay has been replaced as well.

 

Have you checked for power with your $4 test light? That's a little more accurate than "looking for a spark".

 

So I got to test fuse 5 with my test light. I removed the fuse and with the car running the left side lit up but the right side did not. Where should I go from here. The fuel gauge does work if that is pertinent info.

Thanks again,

 

If you remove the fuse and you have power on one side but not the other -

The side with power (on the fuel pump circuit) is getting power from the fuel pump relay.

The side without power - is going to the pump. There will be no power on that side of the fuse holder.

With the fuse in, do you have power at the wiring to the intank pump in the trunk?

 

I will check that next. I was under the impression that one side powered the main pump and the right side would power the pre pump. Must of misunderstood the information from cleanflametrap I found. Thanks for continuing to respond

 

Okay,

The fuse is back in place and the car started right up again. I tested the power to the pre pump with my test light and we have power!

The ground wire seemed a little loose, not too much, so I plan to clean that up and tighten to ensure a good connection. Is there another ground that I should be aware of that might be a problem?

Also, would testing the pump with a battery directly for power be a good idea, use a voltage meter or should I just pull the pump to check all connections. I can’t remember the exact brand I used (it was not Volvo) but it was an entire sending unit and pump replacement. I really do not hear or feel any vibrations leading me to believe the pump is running.

Thanks again guys!

Also as a side note, I found a beck/arnley coil replacement that was Made in the USA. Would this be good to have on hand?

 

I've always used a stethoscope to hear them run if they are too quiet to hear with the naked ear.

 

Should I place the stethoscope to the top of the pump or under the car at the tank? Do they really run this quiet in the tank?

 

Also, does the car need to be running or should I just have someone turning the key while I listen? Thanks again so much!

 

Apply power or run the car - and listen above or below - wherever you can hear it (or not)

 

Would it be okay to loosen the bung nut lock to watch the pump run or not? I have the cover removed from the wagon so access should be easy as long as I clean the area first. Is that a good idea?

 

Sure, I've pulled them out and run them in a pan of gasoline before (makes a smelly mess) - but if it's running you should be able to hear it. If it's running (after hot wiring it) you can disconnect the fuel line feeding the main fuel pump and view the output. (makes a mess also) Don't recall an easy way to check pressure near the main pump, older cars did not have a fuel pressure connection there. Later cars do.

 

I like the idea of disconnecting the line at the main pump to test pressure. Thank you so much for the guidance and encouragement. I need to get under there anyways to check/change the differential. I figure I will replace the seal as well. Also plan on inspecting the carrier and transmission mounts. Any additional advice? This has gone a long way from a fuse discussion!