i got in my car today and it wont start. read the manual and traced it down to the fuel pump. if i jump the 5 and 7 fuses like it said i can hear the pump in the back but it still wont start. i only cranked the motor 2 or 3 times because i dont want to kill the battery. am i not cranking the motor enough. could it be a bad fuel pump relay. is there a way to test.

tried a jumper wire at the fp relay and the fuel pump did not turn on. also took the relay apart to see if it would click when starting and it didnt. it would connect if you manualy pushed it (no pump though) and then disconnect once the ignition was turn off. its wierd that the pump comes on when you jump the fuses but wont if you jump at the relay.

What year is your car? (it makes a difference)

And what terminal(s) did you jumper at the Fuel relay?

What manual are you using?

Too much to guess about at this point.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

83 240dl
87 & 30 (pump comes on)
haynes repair manual
boy do i feel stupid, i had the wrong relay off. no wonder the pump wouldnt come on, i was testing the system relay. so that would mean that the relays bad, right? car still wont start hot wired though. do i need that relay for the car to run or is it something else.

The System relay should "pick" as soon as you turn the key ON.

If it does, and the ignition is OK, the fuel relay should pick when cranking.

Based in history, I'd suggest a careful examination of the 25A blade fuse up near the coil, including the fuse holder contacts and the wiring at Battery +.
(Voltage from the 25A fuse is required to pick the System relay and to power the pumps if/when the Fuel rely picks.)

Check Fuse 12 and its contacts too. It's required to pick the Fuel relay (the ECU controls the relay by grounding it when Coil pulses are detected.)

I'll look at the Haynes to see if there is something I can refer to later, but I much prefer the Bentley manual & diagrams. Let us know what you find.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

12 fuse was blown, sure that happened when i jumped the system relay instead of the fp relay. replaced it. checked the 25a fuse and wire all the way to the relays. ok. check to see if i had spark and i do. the system relay doesnt close when i turn the ignition. could that be the bad relay.
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83 240dl

"the system relay doesnt close when i turn the ignition. could that be the bad relay."

It could be, but that notorious 25A fuse/holder/wiring is more likely.

Can you test for voltage at terminal 30?

If it's there, it should also be seen at 86 (coil+) and at 85 (coil-), until Key the ECU grounds 85 from ecu pin 21 when the key is turned on.

Actually, it's easier just to swap the Fuel and System relays if one is suspect. Try that and let us know what you find.

I dug out my dusty Haynes, if you're using the diagram on page 4A-27.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

tested the voltage at 30, 12.2. checked for voltage from 86+ to 85-, i think thats what you meant. or was i suppost to go from 30 to 86 or 85. also couldnt i test relay with ohm meter.
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83 240dl

Sorry if I wasn't clear about the voltage checks.

Swap relays and if the new "System" relay still doesn't pick when key is turned on, then try the voltage testing.

Check for voltage at 30 (from 25A fuse), then at 86 (jumper from 30), then at 85 (reading thru coil from 86).

If you get voltage all the way to 85, that point should go to 0V under ECU control when Key is turned On -- and the relay should pick.

If the ECU doesn't ground System relay 85 with Key On, you still may have a fuse 12 problem, because the ECU needs +12 at pin 18 to get started. This KO (Key On) +12V comes from fuse 12.

Look at the diagram and you can see where the Blue/Red wire at Fuel relay 86 (from fuse 12) continues on to ECU 18. You should see that +12V at Fuel relay 86 when the Key is On.

If not, check/clean fuse 12 holder contacts.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

was 12 fuse, cleaned it and it started. fuse blew in about 5 sec.
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83 240dl

On you car, fuse 12 doesn't connect to any AC circuit.

Besides the fuel relay and ecu, it powers:

driver's seat heater
rear window defrost heater
back up lights

Try unplugging the fuel relay, then put in a new fuse and see if it blows when you turn the key on (not trying to start, naturally).

If the fuse still blows, it's not the fuel relay that's doing it (although the path to ecu 18 is still active). So it could be the ecu (not likely), or any one of the 3 items above.

If it doesn't blow (with fuel relay unplugged), then the relay must be doing it. Try substituting the system relay in its place -- just to see if the fuse stays OK.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

it was a short in the a/c. i turned the a/c control off and it didnt blow the fuse. i think i will just disconnect the power to that piece, the a/c does not work anyway. i must have done something to the wiring when i was tighting the belts. i also plan on bypassing the a/c condensor, three of the bolt holding it in have sheared off. i think if i turn the power steering pump pulley around it will line up and i can just get a longer belt. thanks guys, this site is great. thank god for brickboard, i sure cant afford to take it to the volvo dealer to get it fixed. but who could.
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83 240dl

This belt works on an '87, but I think the pulley alignment may be some different on your '84.

7520 Gates XL 11A1320 It's long enough to drive everything, skipping the AC comp.

On the '87 (with harmonic balancer 3-groove pulley), the normal alternator belt is in the back groove. This long belt is in the middle groove, to alt pulley, WP pulley, PS pulley, and back to the crank pulley, which now has no belt in the front groove.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

i think i can move the pulley out with a one inch spacer and some longer bolts and it will line up. another question, when its warm out and the cars been running for awhile it hesitates. i havent ran it long enough to see if gets as bad as it did before i replaced the intake manifold gasket. it wouldnt go at all, acted as if the throttle was broken, i would give it gas and no responce. i was reading a couple of posts about temp. sensetive parts. any ideas.
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83 240dl

Looks like Scott was right and I was wrong about the AC and fuse 12.

I overlooked it by tracing from fuse 12 on the diagram, which shows no AC connection. I should have looked at the AC Delay relay itself, which does show fuse 12 feeding it, and thus the AC clutch.

Glad you are back in business.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

If it blew in 10 seconds instead of five I'd guess the short was in the green wire to or within the A/C clutch. 10 seconds is the time the delay relay takes to engage. If so, try a new fuse, but with the A/C control fully hard brute-force to the OFF position.

Scott

You should know that if there is no spark the fuel pump relay will not engage.
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David Hunter