Please read entire post I’m really stuck and i’m ready to call it quits.

Little over a year ago this motor over heated and took a head gasket. I could not due the repair at that time due to money problems. So the car sat 1 year.

So I just finished the rebuild I replaced all gaskets and used new bolts everywhere. Heads, exhaust, intake manifold. I had the heads cleaned and pressure tested by a machine shop just to make sure nothing was cracked. . I cleaned the valves and lap’ed then in. New valve seals, New plugs, new wires, and new coil packs (3). New radiator and new hoses (both) upper and lower. New temp sensor, new thermostat, and new radiator cap. I also replaced the water pump and put in a new belt.

I Pressure tested the coolant system and it held pressure over night (no leaks) I filled the motor with new oil and new coolant. I had to replace the battery dead and would not take a charge. I started the car and it started right up and sounded good. Using the bleeder valves I took my time to burt the air out of the coolant. I had the heat on high to get the air out of the heater. The refill procedure says to run the car until with the heat on until the coolant fan turns on and off 3 times. The fan never turned on. I drove the car to a gas station to get some fresh gas and drove it home maybe 10 miles round trip. I was very happy the car seemed to be running well. So later that night I took it out for another test drive and again before leaving I started the car and opened the bleeder’s and made sure no air.

Now driving the car the 1st 15 miles everything was ok temp was running normal and then the car seemed to start sputtering and i looked at the rpm’s the gauge was going crazy up and down very unstable and the battery light would come on and go off It kept running so I kept driving and this problem would come and go the rest of the way home about 15 miles. As the motor was sputtering I noticed the temp was going up higher and higher as soon as i pulled into my driveway the car died. It started right back up but was hot not over heating but it was hot.

The fan never turned on. So I started there not knowing if the sputtering was causing the high heat or the high heat was causing the sputtering or if they are not related. I tested the relays all 3. I opened them the manually triped and the fans turned on and the speed would increase. I also pulled them and tested the coil with a 9v battery and the relay would turn on and off. I’m guessing that this might be a computer problem but do not know. Are the problems related? I dont know But I could use some advise as to where to go next. Also its a front wheel drive so the cooling fans are electric.
Thank you for your time
Dave thank you for reading. The coolant temp sensor is the only thing other that the computer that turns on the fan (that I’m aware of) and the relay does test good and if I manually trigger the relay’s I can turn on 1 fan or both fans and at both low speed and high speed. This one really has me stuck.