Help....working on a 1985 vette with a 1988 vette engine. Vette shows 130K miles. Rad has been re-corded and cleaned. Installed new fan and replaced fan relay. Fan does not come on at all even when I turn the A/C on. Only time the fan comes on is when I jump the relay. All I want to do is get the fan running, stop the overheating and sell this baby so that I can start working on my 81 vette.....