1987 560 sec mechanical info
 

I recently installed new aux fan and it works properly and would go on when engine reached certain temp. now allof a sudden fan goes on immediately whenkey is turned on. Also I don't think a/c is engaging. Could this be an a/c sensor problem ? is there a way to test sensor? Also low oil liight stays on. Any knowledge on this problem or diagnosis would be greatly appreciated. thanks theo

On he fan, if it comes on at a low speed (as compared to the spped the fan runs with a hot coolant temp)it probably is a stuck high pressure switch (or the system actually is overcharged), on the oil level, if the level is good you can assume probably the oil level switch.
Gilly