Cooling fan problem?

[sprocket]

This problem is with my '96 daily driver. Now that it is finally warm out a cooling fan issue has popped up. The fan will not turn on until the temp is at least to the O on "NORMAL" and then I think it is on a slow speed. The temp then does come down some but it doesn't take much for it to climb again because the fan doesn't come on when it should. If the max AC is running then the fan is on. I'm not sure if it is always on if the the temp control is set to auto and the temp is set low enough that you would expect the AC to be running.

If I turn the climate control to off, then the fan doesn't run until the temp is too high, like I already described.
This car has a 180 thermostat, but I'm pretty sure that doesn't have any bearing on the situation.

I'm also surprised by how high the temp can get in stop and go traffic. I've seen it climb in the winter a couple of times. Now that it's warm out I see it more but it's kind of random. Maybe I'm barking up the wrong tree and the problem is actually a partially clogged radiator. It's NOT a head gasket problem.

 

[chris2523]

sure its actually running hot and its not just the temp sensor that's whacked out?
they do go bad. and the gauge is separate from the pcm as far temp readings go.

the fan doesn't do its thing unless you set it on max i believe, so that's normal.

clogged radiator doesn't make any sense. the fan would still come on at the appropriate temp, but it wouldn't cool. the temp sensor isn't in the radiator.

 

[slowmkviii]

Like Chris said possible temp sensor either one
You can swap fans in 20 min or so with the other mark.
When is the last time you flushed the coolant?

 

[sprocket]

The coolant was drained last year but not really flushed. There are two temp sensors right? I believe the one for the gauge is correct. It's the one for the pcm that is suspect correct?

I have a code reader that reads live data and that should show the temp sensor reading that is going to the pcm and if that doesn't match what the gauge is showing, then the sensor must be bad.

I'm convinced the gauge is right because it sits exactly where I would expect it to most of the time and it reacts appropriately to when the fan eventually does come on.

Another test I will do today, if it gets warm enough out, is to run the A/C so the fan is running. I will hit stop and go traffic crossing the river on the way home. If the temp climbs very much then, with the fan running, I will know I have another problem.

Question: With the A/C off, at what temp should the fan turn on and where would the gauge read?

 

[chargerxr]

I would check the cooling fan connector, as they are a known problem, possibly making a bad connection. If the fan seems to run slow all the time, the motor could be on it's way out, drawing to many amps and burning the connector.

 

[driller]

The fan does indeed run anytime the AC is on. It is controlled via the VCRM to run at 50% minimum and should vary speed up to 100% depending upon AC pressure and engine temperature. If the AC is set to MAX AC, the fan should run high speed full time.

The only time the AC is "off" is when the EATC is in the OFF or VENT position.