So my 94 Acura Integra GSR has an issue with the cooling system. The fan will come on when I turn the AC on but not on its own. I replaced the thermostat already. I was going to check with my meter but my 9v is dead in my meter. So before I head out I figured I'd get any input so I could pickup anything I might need.

 

there is a thermo switch or coolant temperature sensor. i cant remember what its called but check that out. also you should have 2 fans under your hood. one for a/c and one for radiator cooling. the radiator cooling fan only comes on once the engine is up to temp. i believe somewhere around the midpoint range on the gage.

 

It's called the ECT switch, it supplies a ground to the rad fan relay when engine temp. reaches about 190-200 degrees F.

As mentiond, you have a rad fan and a condensor fan, only the rad fan turns on when engine temp. is up, both the rad fan and condensor fans turn on when A/C is on.

If both fans turn on when A/C is on then the rad fan and rad fan relay must be good, along with all wiring and fuses, that only leaves the ECT switch and it's wiring.

To test, unplug the ECT switch, start the car, install a jumper in the ECT switch plug to connect the black and green leads, if rad fan turns on, replace the ECT switch it is bad.

If rad fan does not turn on, trace the green lead from the ECT switch to the rad fan relay and find the break. 94

 

Yeah I replaced that as well. Someone told me it could be a bad one out of the box. I haven't checked the wiring yet.

Basically what happened was the thermostat went bad and the car overheated. The pressure cracked the old radiator so I replaced it, the thermostat and the ect. Also I'm not totally convinced its flowing water through the radiator well but if you are moving it never overheats so I guess it has to be doing something. So now I can't get the rad fan to turn on by itself. Both fans do turn on when I turn on the A/C. Thanks for the help, I'll check the ect wires and possibly buy another.

 

if you dont think coolant is flowing the only possible cause of that would be the water pump. although i have never PERSONALLY seen one fail on a honda. the design of them is so **** simple there really isnt much to go wrong. like fcm said check the fan relay. or do like my buddy and run direct power to it and put a switch in the cabin.

 

fan relay is working if, as fcm stated, both fans work with ac on. which they do.
just do as he'd said. jump the ect switch connector with a paperclip. if fan operates, replace the ect switch. if not, trace the wires and find the break

the car is more likely overheating in traffic because the fan isn't engaging. not because of coolant flow

 

Yeah it only overheats if you don't have the AC on otherwise the temps are fine even stopped. I jumped the fan and it came on fine. So I called the place i got the sensor and it turns out I bought 2 and i guess both were bad out of the box? I mean if jumping the wires starts the fans it has to be the sensor but its weird i got two in a row bad out of the box. I'm taking the one I have in there now up there and they are giving me a new one.