PRO50SC

Corrosion inside the radiator. You'll know it when you see it. See how the ends of the tubes in the pic are nice and clean. That's how it should look. It will prolly be full of corrosion on the ends if it is old and or hasn't been taken care of.

91LXStang2727

Ok thx for info an pic im going to take a look in the morning.

90GTRagtop

Another way to check the fan clutch is to take a rolled up newspaper and touch the spinning fan blade from the motor side with the motor running. If the fan blade stops turning, the clutch is completely shot. Note; Don't try this trick with body parts, only a rolled up newspaper, and be careful to stay out of the belt.

Twister

the stock sending unit is a dummy one, it has a few positions...if it moves a lot, it could be the constant voltage regulator behind the dash