Cooling Fan Problem
Powerefx
03-10-2005, 10:14 PM
Aright guys i have a cooling fan problem on my 93 escort wagon. At first i thought it didnt work at all, then is put power straight from the battery to the fan and then the fan started working. When i turn on my a/c the fan also starts working. However the fan doesn't work when the engine gets hot like it is supposed to. I was wondering what can be the cause fo this. I need alll possiblities available.THNX
curtis73
03-10-2005, 10:34 PM
The most obvious answer is the coolant temp sensor. Find a shop manual for the car and it will tell you how much resistance it should provide at certain temps.
Test continuity of the sensor body to the block. Sometimes they corrode and don't ground properly.
its also possible that the relay for the CTS is separate from the relay for the A/C turn on, etc. if so, the relay could be bad.
I say, bad CTS first, then look for other electronic mishaps like shorts, loose wires, etc.
Test continuity of the sensor body to the block. Sometimes they corrode and don't ground properly.
its also possible that the relay for the CTS is separate from the relay for the A/C turn on, etc. if so, the relay could be bad.
I say, bad CTS first, then look for other electronic mishaps like shorts, loose wires, etc.
Powerefx
03-11-2005, 12:27 AM
well the temperature gauge works fine, and i just bought a new CTS, so could it be the wiring to the cts, but if it was, how would the gauge work?
curtis73
03-11-2005, 12:57 AM
Most of the time the CTS for the gauge is different from the one for the computer/fan. Sometimes they are directly inside the fan itself, or in between the fins of the radiator.
But yes, it is wise to assume that the wiring downstream from the CTS needs to be checked. When the engine is hot enough that the fan should be running, start testing wires, sensor resistances, and see how far you get 12v to the fan. Could be a corroded pin in a connector.
At this point a wiring diagram would work wonders at diagnosis because it would answer all of the questions.
But yes, it is wise to assume that the wiring downstream from the CTS needs to be checked. When the engine is hot enough that the fan should be running, start testing wires, sensor resistances, and see how far you get 12v to the fan. Could be a corroded pin in a connector.
At this point a wiring diagram would work wonders at diagnosis because it would answer all of the questions.
Powerefx
03-11-2005, 01:06 AM
well i do have a wiring diagram, cant figur it out though,
maybe i can scan the pics of the manual and send it to ur email, and u can take a look at it if its not too mouch trouble?
maybe i can scan the pics of the manual and send it to ur email, and u can take a look at it if its not too mouch trouble?
curtis73
03-11-2005, 01:35 PM
It wouldn't do me any good since I don't have the car. All you need from the diagram is to find out what wire from the fan itself goes to the fan's CTS or relay. If it says gr/yl then you know its a green wire with a yellow stripe.
Use the diagram to trace connections back until you get 12v power. You're probably not getting power to the fan, so use the diagram to see what's next upstream; might be a connector on the firewall, a relay, a switch... test to see if you get 12v there. The point where you finally get power is probably your faulty component.
Use the diagram to trace connections back until you get 12v power. You're probably not getting power to the fan, so use the diagram to see what's next upstream; might be a connector on the firewall, a relay, a switch... test to see if you get 12v there. The point where you finally get power is probably your faulty component.
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