What and where is located a ac compressor coil ?

[zodpowercy]

I have a s15 with a sr20det redtop swap from a s13 and the problem is the ac stopped enganging.I thought that it needed a refill or there was a leak in the system but when i went to a ac shop they told me the problem was the coil needed replacing.
Where is the coil located ? I assume they were speaking of the clutch coil that is located inside the pulley of the ac compressor ? Is it better to replace the whole ac compressor as they told me a much higher price than that of a used ac compressor...?
Sorry if my questions seem stupid but better ask then be sorry...i learned the tough way...

[Kingtal0n]

Yeah it sounds like the electro-magnetic coil behind the pulley, you should be able to find another used S13 compressor $50~ takes about 20 minutes to change. I used to have 3 of them sitting around as spares when I had my S13.