Lumina APV Open Loop

1990 APV 3.1 liter motor, 120,000 miles. Cooling fan will not come on by it self. It does come on after about 1 minute when turning on A/C. I have replaced the fan, relay, 2 cooling sensors and thermostat. My question is if my computer is stuck in an open loop will this cause the fan not to come on. If so, will just disconnecting the battery reset this? My temp gauge will go up to 3/4 and the fan will still not come on. I am out of ideas. Thanks for any advise.

I'm pretty sure the fan isn't supposed to come on until about 230 degrees. Does that have heavy-duty cooling, with 2 fans? If so, the secondary should come on immediately when the A/C switch is on. You could try resetting the computer by disconnecting the battery for about 15 minutes and see if anything happens.

I'm pretty sure the fan isn't supposed to come on until about 230 degrees. Does that have heavy-duty cooling, with 2 fans? If so, the secondary should come on immediately when the A/C switch is on. You could try resetting the computer by disconnecting the battery for about 15 minutes and see if anything happens.

There is only 1 fan and it does not come on immediatly when the A/C is turned on. I think that is probably normal as it does come on in about 1 minute. I will disconnect the battery and see what happens. Thanks for a quick response!!

Just an update on my problem. Resetting the computer did nothing to correct the cooling fan problem. A local machanic did get me a wiring diagram so I could check all associated wires and they checked out OK. Evidently that part of the circuit on my computer is bad. I just tapped a wire with a switch to the relay to turn it on manually. It works for me because I'm not about to go out and buy another computer. You win some , you lose some.