In Nov 2021 my blower mower melted fuse 16. I bought a new motor and bypassed the fuse that was melted to the panel by following the below post found on BB.

*****
Melted Heater Blower Fuse

[Inquiry] My 1984 740 Turbo has a melted fuse that protects the heater blower/ac circuit. The fuse did not blow, but instead heated up enough to melt the fuse and the surrounding fuse box. Suspecting a short to ground fault within the circuit, I have examined the wiring and do not visually see any bare wire. I have replaced the blower motor, relay, and the fan motor switch without solving the problem.

[Response: John Sargent]This can be fuse number 14 (early 740s) or 16. The fuse and fuse holder are simply overloaded in the basic design. There is too much current draw on the fuse holder. It was fine when new, but too many heating cycles weaken the grip of the fuse holder on the fuse after 15 years. This is a very common problem on 700 series Volvos. Unless your car has over 200,000 miles on it, the only part of the central electrical unit that will be bad is the fuse holder for fuse 16. Nothing lasts forever, but fuse 16 is the weak point. The wiring to the CEU should be fine, although high mileage cars can have troubles at other relay sockets. You have two choices:

Replace the entire fuse block panel with a new, or good used unit.
Buy a new fuse holder and power the AC and heater with it
If you choose option 2, you must pull the central electrical unit out and turn it over. Splice a fuse holder into the lead supplying power to fuse 16. Splice the load side of the new fuse into the black lead supplying power to the heater and AC unit. You must continue to supply power to fuse 16, as fuses 14 and 15 are fed from the supply side of fuse 16. It is possible to intercept those black wires elsewhere, but it is easiest for me at the CEU. If you can get enough slack in the black wire which supplies fuse 16, a red wire nut works great for spicing the new fuse holder in and keeping fuse 16 supplied with power. The fix will be less than $5 US.

****

I bypassed 16 with the inline fuse and jumped power back to 14 and 15 as suggested. Since I did the fix back in January, I did not test out the AC. Once summer came around, and it was time to use the AC again, I discovered that it no longer worked.

When I switch the controls to AC mode and slide the temp lever over to cold, nothing happens. Usually, you'd hear the compressor kick on and moments lake the fridge air of northern europe would be blasting you in the face (usually with small bits of black foam for good measure). Since the replacement, the compressor never clicks. I assumed that fixing the main issue would be enough, turns out I was wrong.

The car has less than 75,000 mi on it and I just had a full AC service last summer for the first time in decades. I had purchased it from the 2nd owner who had stopped driving it years ago. It blows strong and cold when in good working order.

Any help that can be provided would be amazing. Thanks in advance!
-Andrew