Fan on....always.....but why?

Still fairly new to my XJS, I have noticed that as soon as I turn the ignition on, the radiator fan comes on. I started fishing around under the bonnet and found a wire connecting what looks like the air conditioning relay (blue-green) to the radiator fan relay (blue-blue). The AC cooling is not currently working, but I will leave that for another day.

I am assuming that the fan was not coming on when it should, so a prior owner has hard wired it on via the AC relay for some reason. Is this just a lazy fix that could be permanently sorted with either a new relay, or a new temperatire sensor? I would appreciate any and all feedback before I get stuck in this weekend.

There were several iterations of cooling fan circuitry over the years. What is your exact model, year, and engine?

Cheers
DD

Hi , my 1990 xjs v12 the right fan always comes on when ignition on . The left fan comes on to cool down car after turning car off. Set a certain temp. Gina

Sorry, I should have said. It is a 94 4.0 2+2 Cab