Solara Radiator Fans

[cjsager]

So first of all let me just tell you I don't know a lot about cars but I am learning. I drive a 2001 Toyota Solara 4 cylinder (that much I know) My car has occasionally run hot over the past couple of years. 2 years ago I had to have the radiator replaced (after that was when I noticed the problem). So it is usually when I am sitting with the motor running. When I notice this I turn the AC on and go. I have just had the thermostat replaced and still having the same problem. Should it be doing something else or is this just the way things are?

Thanks,
Candice

[Chris Crash]

When you're idling, or not moving fast (say through a drive-thru), the radiator fan should kick on. If not, then that's why you'll get hot. I used to have the same problem on my 97 Camry. Wired the fans up to a switch and voila. But I'm sure there is an easier fix.

[fenixus]

check your radiator fan switch - it's a coolant temperature sensor sitting in bottom of radiator on passenger side. unplug the connector and see if fans come on (they should when disconnected and IGN ON).

now, when car gets hot (can you see that on dash gauge?) e.g. after heavy city driving or highway driving and then idling in parking lot, those fans should come on, if they don't this means that switch is bad. as a band aid you can keep it disconnected for now, so fans will be running all the time, but this is not a solution, just a temporary patch.

also check your fuses and relays in Main Engine Room fuse box, under hood, on driver side. there is a fan relay for each of fans (total three, 2 on radiator and one for cabin vents).

also there are fusible blocks (square, 30A or 40A with translucent top), at least one of those fusible blocks (it's a Female Maxi fuse or FMX type) is for fans as well (CIR or CDS if I remember correctly). one is for Condenser fan (one of those on radiator, passenger side IIRC) and there is another for the other fan I think.

if you find any broken fuses or fusible blocks, just get them new from local AUtozone or Advance Auto or NAPA.
if you suspect a bad relay, you can swap it with another same looking (some are interchangeable) to see if it helps.
generally bad relays are stuck in one position and do not switch circuits when energized, sometimes knocking hard on them (while energized) makes them click, when that happens it means it's bad.

alternatively relays can also be tested with 2 wires connected to battery terminals with alligator clips, they should click when control circuit gets energized.

edit:
just realized you said when turning ac on helps stabilize engine temp. it means that those rad fans come on when ac is running, so both rad fans spin, correct?

if that's the case then check that radiator fan switch (aka coolant temperature switch), most likely it's bad.