k.lzuhl@gmail.com wrote:
> We have a 1998 V70 with a fuel pump fuse problem. Earlier this year,
> the car developed a problem where it would occasionally blow out the
> fuel pump fuse and refuse to start. At first, replacing the fuel pump
> fuse would fix the problem for a few months, but then the fuel pump
> fuse started blowing more and more often. (It seems to blow the moment
> you start the car - so, we replace the fuse, start it up and it runs
> fine, until you turn it off and have to start it up again! The fuse
> never blows while the car is running.)
>
> Now the car is almost undriveable, it's so unreliable and goes through
> so many fuses. Sometimes we use two or three fuses just to get it
> going. We have taken it to two independent garages. The first could
> find nothing wrong and suggested we replace the 10 amp fuse with a 20
> amp fuse (which we did, but it didn't seem like very good advice).
>
> So we took it to a second garage, which also could find no mechanical
> problems, but they also checked the codes and said the car comes up
> with all kinds of weird codes that make no sense. The second garage
> suggests it's a software problem and that we take it to a Volvo dealer,
> because perhaps the software is causing the fuse to blow.
>
> Anybody heard of anything like this happening before with a V70?
Are you sure it's a 10 amp fuse? In my '98 S70 it's a 20 amp fuse for
the fuel pump an ignition combined (very dumb combination).
Anyway, mine had a very similar same problem. The fuse wasn't exactly
blowing though, the wire inside that is supposed to break was obviously
fine. What was happening was the fuse was getting so hot that the
plastic part was melting. This made it change shape, which made the
spade contacts not make contact anymore. Pretty strange. I figured the
plastic fusebox chassis was weak and making the new fuses' spades not
make very good contact in the first place.
A few months ago when I first tried this I was down to blowing that fuse
every one or two trips, and sometimes more than one to get the car
started. Just like you, once it was running it was fine.
My solution was to take a brand new fuse and slightly bend both spades
in opposite directions from each other. It seems to work. The car only
failed to start once since then, and taking out the bent (bent by me,
not by itself) fuse and putting it right back in worked. Since then no
problems. I also bought a new battery over a month ago and the car
started much quicker (before the engine would turn over at least a few
seconds before catching, now it cranks much faster and catches immediately).
Right at the same time my air conditioning compressor intermittently
failed to come on at all. The problem was pretty obvious when I found
it worked if I pushed down on the A/C relay. This is in the same box as
the problem fuse (the one with about half a dozen relays and half a
dozen fuses, next to the one with a few dozen fuses). Bending the
spades on that relay did the trick, no problems since then.
What can I say... sometimes I wonder if Volvo, Bosch, and Lucas made a
secret pact in 1998.