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"When I apply 12 Volts directly to the pump, it hums and pumps gas to the hose going into the fuel filter in the firewall."
• Good — then you know the pump will run when 12V is applied to it.
"Also, I jump fuses 6 and 7 and no buzzing;"
• That's because fuses 6 thru 10 are all connected to battery +. Fuse 7 does provide 12V to the pump thru the Fuel pump relay. But only when the Fuel pump relay is energized during cranking & running.
[Check fuse 13 for clean, tight contacts. It powers the Pump relay coil.]
"jumping fuses 5 and 6 activates the in-line fuel pump."
• That's good (if you mean the Tank pump) but it should also activate the main pump. However, you don't say which fuse 5 contact (left/input or right/output) got the applied voltage from fuse 6.
[That could make a difference depending on fuse and contact conditions. Your statement implies that the Main pump wasn't activated. Was it?]
"What am I missing?"
• Well, one thing I see missing is "continuity" when you post under many aliases, such as...
1980 242
VolvoSF
Volvo Love
23Jr
1986 Volvo 240
Oil Light On
Volvo Man
240 Fan
Volvo Red
Me
Volvo Lover
Volvo Red
...and then ignore (or don't respond to suggestions) like the one I made back on 1/28 when you (as "Volvo Love") asked how to remove the "black plastic" line from the tank unit barb. I spent several minutes on a response describing how I have successfully done that job by cutting and splicing, but got no reply. And the 7-to-5 fuse jumper I also suggested in that same 1/28 thread would have told you then that the Main Pump wasn't getting power. But as far as I know you never tried it.
Remove the back seat and test (fuse 7 to fuse 5 jumper) for 12V at both sides of the Yel-Red wire connector on the left side of the under seat floor panel.
[That Y-R wire should feed 12V from Fuel relay terminal 87 to the Main pump.]
[If no 12V at that connector, I think there's another one under the left side of the dash. Not sure - it's been a long time.]
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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