electrical mystery

[Art McGinn]

every once in awhile we discover the battery (otherwise ok) has gone
dead in our '97 960 wagon. when the ignition is turned to the starting
position, there is a rapid clicking sound but the engine won't turn
over. a jump-start gets it going again -- until the next time it
happens, sometimes weeks or even months later but always mysteriously.
one past clue has been the discovery of a fan running somewhere inside
the car when we climb in. the fan, location unknown since no rush of air
can be felt, seemingly has turned itself on and run-down the battery.
the only other clue, if it's a clue at all, is that the light/s which
illuminate the position of the automatic shift lever -- reverse, drive,
park, etc. -- flickers on and off unpredictably, suggesting a short
somewhere. we assume that at the bottom of our mystery is, in fact, a
faulty switch or a short which turns on fans or who-knows what else. we
had a volvo-oriented garage check this awhile back but their high-tech
equipment could detect no electrical problem anywhere (but it did accept
my triple-digit check for its troubles). now the problem is back again.
are there any wizards out there who have confronted any such hobgoblin?
if so, thanks for any suggestions. art

 

[James Sweet]

every once in awhile we discover the battery (otherwise ok) has gone
dead in our '97 960 wagon. when the ignition is turned to the starting
position, there is a rapid clicking sound but the engine won't turn over.
a jump-start gets it going again -- until the next time it happens,
sometimes weeks or even months later but always mysteriously. one past
clue has been the discovery of a fan running somewhere inside the car when
we climb in. the fan, location unknown since no rush of air can be felt,
seemingly has turned itself on and run-down the battery. the only other
clue, if it's a clue at all, is that the light/s which illuminate the
position of the automatic shift lever -- reverse, drive, park, etc. --
flickers on and off unpredictably, suggesting a short somewhere. we assume
that at the bottom of our mystery is, in fact, a faulty switch or a short
which turns on fans or who-knows what else. we had a volvo-oriented garage
check this awhile back but their high-tech equipment could detect no
electrical problem anywhere (but it did accept my triple-digit check for
its troubles). now the problem is back again. are there any wizards out
there who have confronted any such hobgoblin? if so, thanks for any
suggestions. art

I suspect an intermittant short somewhere, a terminal too close to another,
a chafed wire contacting the metal body, something like that. It's also
worth checking to make sure the glove box and engine compartment lights are
turning off when closed.

 

[Perry Noid]

is there an electric fan to defog the rear window? That was a popular item
some years back, although I don't know if volvo used them or not... anyway,
that would be a potential reason for the battery running down overnight.

If you have such an option installed, it might be worthwhile disconnecting
it for a while and see what happens... Not sure they were ever all that
effective anyway!

 

[Art McGinn]

thanks for the feedback, fellas. a new battery has, at least
temporarily and hopefully permanently, put the gremlin in its place.
what the connection was between an exhausted battery (as it turned out)
-- it was, amazingly, the original equipment battery with a volvo
logo, making it apparently 10 years old but still basically functioning,
at least most the time! -- and strange electrical behavior is a little
unclear. but we shall see. cheers, art '97 960 wagon.