My 87 samari is overheating. Thought it was the fan clutch so i wired it so that it would have to turn. Ran so cool the temp guage would not read. Replaced the clutch with a new one now it runs hot again. Thermostat is open and the radiator seems to have good flow when the cap is off. What gives? Any suggestions?

try replacing the cap and thermostat just to be sure. they are under $20 for both and if they have not been done in awhile its always good preventative maintenance.

I'm with black and tan, do the easy and cheap stuff first. 

Will try this first. Thanks.

is it actually overheating or is does the gauge say hot???

Checked temperature inside radiator with extra after market guage and sending unit i have. Matching whats showing on dash gauge. Wondering if the water pump is weak or about to go. Checked weep hole no visual signs of leaking and looking in radiator seems to be moving fluid fine.

does it overheat when moving at speed? because at speed the fan is really doing nothing its mostly airflow from moving. if its overheating while moving there has to be an internal problem. I have seen the blades on a water pump almost missing due to lack of corrosion inhibitors in the coolant and the blades rusting out over 20 years

 Overheats 2 or 3 miles into a run no matter how fast you are running. Got a thermostat and cap today try it out and see if it helps.