fuel pump relay?????

[infinity1]

hi all,problems with my 740 not starting led me to believe it was the fuel pump relay,took the one out of my father in laws 740 2ltr and it started fine,so sorted, new relay,just got one s/hand off ebay plugged it in..same problem,wont start.....written on the side of this relay is,'fuel pump relay 1990 940 hreg' and its white.would this make any difference as both the broken one and the one out of the father in laws were green,?????my 740 is a 2.3 and my father in laws is a 2ltr,anyone shed any light on this,im getting a bit annoyed now..or should i have bought a brand new one???
p.s the fuel pump still works fine.

[Peter Milnes]

If the connections are compatible inside the relay you could resolder the connections and keep it for a spare. However I suspect that it may have a different pattern inside it. Some cars were fitted with Rex/Regina sytem which only has an in-tank pump so there may not be a contact for main pump on the relay.

All the best, Peter.

I have intermittant problems with the fuel pump relay on my 740 gle. I just wiggle mine and it kicks back in. It is white and is marked on top "Volvo 12v 898151 Made in Germany 3523608". Hope this in some help. My boy kinda trashed the interior of this car when he went off to college so I just left the covers over the relays off and I wiggle the fuel pump relay when it balks and twist the overdrive relay clockwise when it won't shift.

[PAZ3154]

basicly the green rectangalar relay 3523639 was fitted to earlier cars with the bosch K jetronic fuel system. the white rectangular relay 3523608 was fitted to the later cars with bosch L jetronic fuel system. they both have the same pin arrangement and one will fit in the other's socket but the internals are slightly different. the green relay you require is quite expensive at £40 new. however you should have no problem finding one in a scrappy. or as peter says all they usually suffer from is a dry solder joint next to the spring contact. if you re-solder this they sometimes last for years

I had a bit of time last night so I pulled the fuel pump and overdrive relays, popped them open and did a bit of resoldering. Resoldered all the joints in the fuel pump relay and those that seemed to be discolored or high current bearing in the overdrive relay. Definately fixed my overdrive problems - no more up arrow idiot light and transmission is upshifting smoothly. Jury's still out on the fuel pump relay since it was always an intermittent problem - so far, so good though.

[turboboy]

Thought I read something on this site about the early green relays giving trouble and it was recommended to change to the later white pattern, being a direct swap.

Anyway, early this year my 740 Turbo would not start and having read various posts immediately thought "relay". On investigation someone had already put in a white relay. Problem turned out to be that whoever fitted it had obviously found that a connector/wire in the mounting board was overheating, had cut it off and replaced it with the female part of a standard, crimp on spade connector. When I pushed the relay back in it pushed the connector down (as it did not have the "tangs" to retain it in the board) resulting in intermittent contact. In addition the wire was not properly crimped into the connector. Car would start but not run.

It took my son and I a couple of hours to diagnose this but only 10 min. to fix.

So as well as checking the relay itself I would suggest checking the wiring connections underneath the relay board for overheating and poor connection.