1988 Volvo 760 GLE V6 Sedan with 68,000 original miles...I have problem with my cooling fan It doesn't turn on if I turn on my A/C....the compressor kicks but my fan doesn't...I checked the fuse the relays are fine......the mechanic says "its not gonna turn on if it doesn't make it to its warm/hot temperature." is that true? because my fan works fine on summers because I use my A/C a lot...but then now winter time....I use my A/C for defrosser it dont work...what could be the problem?? i was thinking the auxiliary fan switch?