Hello:

I've owned a number of 240's and my first was a 76 242 DL. On that and
all others the fuse panel was located at the driver side
footwell--although there may have been a secondary fuse panel located
in the engine compartment. I simply don't recall now. I can say there
is no secondary fuse panel in the engine bay on my 93 24o wagon.

Anyway, remove the fuse panel cover in the driver's side footwell.

In the US and Canadian markets the wiper fuse is 16 amperes and is
fuse #2 (second from the top.) This is clearly indicated on the label
on the inside of the cover. The left side of the label indicates fuses
and what they are for in French, right side is in English.

The labeling may vary depending on your country of residence--but my
guess if the location of the fuse will not, as that would make no
sense.

Note: while you have the fuse panel open it's a good idea to remove
every fuse,  clean all terminals with emery cloth of fine sandpaper
and then "squeeze" then together gently to ensure the fuse will fit
tightly.  Late 70's and early 80's 240's were notorious where I lived
for failure of the fuel injection system or erratic performance--which
was nearly always a "loose" fuse (#6) for the FI and fuel pump.

It's also not a bad idea to coat the terminals with a light bit of
dielectric grease.

I still remember an incident back in 1982 when I was on a remote
section of I-5 in California. A woman was stranded with her fairly new
240 and the Triple A mechanic was baffled. 5 minutes later she was on
her way and the Triple A guy (pretty sharp tech) had learned something
new about Volvos. He HAD checked the fuses and they looked good and
"felt" tight but that one was not.

Good Luck!

Doc