Volvo Penta 2010 5.0 GXi; fuel pump fuse

Last Chance II

Recruit
Joined
Sep 29, 2014
Messages
2
Chronic issues with the fuel pump. Current pump about two weeks old. Ran great last week. Started up fine yesterday; ran about 5 minutes at the dock and quit. Blew the 20A fuel pump fuse. Fuse blows only with low pressure pump connected; high pressure pump ok. Connected brand new low pressure pump and fuse blew again. Replaced the low pressure electrical connector... no change. Using jumpers connected only one lead a time to the LP pump; OK so long as both the power and ground are not simultaneously connected. I also swapped the fuel pump relay with the identical one next to it, no change. Anyone with ideas; please let me know. Thanks
 

Saline Marina

Petty Officer 2nd Class
Joined
Sep 9, 2014
Messages
162
If I understood correctly, a used and a new low pressure pump both cause the fuse to blow. I would suspect a short circuit/ground fault with something like a rubbed-thru or pinched wire which is causing a current draw of significantly more than the ampacity of the fuse. You can probably do some detection with a continuity tester with the fuel pumps disconnected as motors can sometimes create erroneous readings of continuity.

Edit: I re-read that you connected power a single lead at a time with no issues which pretty much negates my advice above.

Is it possible the polarity somehow got reversed in the harness connector?

I would also look at the fuse block itself. If there was a corroded high resistance connection there it could be causing localized heat which could contribute to the element popping.
 
Last edited:

Last Chance II

Recruit
Joined
Sep 29, 2014
Messages
2
Well .....I actually bypassed everything..hooked up the existing low pres pump to the battery using gator clips and jumpers....measured 21A. Would seem to indicate a bad pump....but a new pump connected via the wiring harness popped the fuse. The new pump was not installed...just sitting on the deck. Beffled doesn't describe this
 
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