Mustang 2.3 cooling problems

[Big-T]

The car is a 1989 Mustang 2.3 four-cylinder with automatic. I have some cooling problems and have 2 questions:

1. Does anyone know where the temperature sensing switch for the radiator fan is located? I tried following the wires but got lost.

2. The engine never seems to get up to proper operating temperature. I have replaced the radiator (it was leaking), the main hoses (to the radiator), and the thermostat (3 times). The only time it will reach proper temperature is when it is standing still (no airflow through radiator) while idling for a while. As soon as I start driving again the temp gauge falls down to the very lowest end of the gauge range within a few minutes. If I idle long enough while standing still it will eventually reach max temperature on the gauge, since the radiator fan is not working (see question 1. above). It falls down to bottom of the gauge quickly when I start moving though, regardless.

Any advice is greatly appreciated.

Thanks!

Big-T

[DAN-MAN]

Well, I don't have an answer to your first question, but I do have some input for your second. I use to have an old '90 LX hatch 4 auto. The way you described your temp guage acting is alot like mine was. The car never leaked coolant and I never had to replace the thermostat. It never had any problems, even with the guage sitting just narrowliy above the cool indicator. While it was sitting, not moving, it would move up. But when you drove it down the highway the guage would go back down. My guess is that's just how they are. If I were you I wouldn't think about it that much.

Daniel.

[84LX89GT]

If you're not sure your fans are working, turn on your air conditioning, there is a bypass that turns on the fans to extract heat from the condensor so your car blows cold air.

Try doing that and see what happens. You could also try getting a haynes, or chilton manual and seeing where the fuse is for the fan and if it's not working you could try tapping on the fan with a hammer or blunt instrument to see if the motor is starting to build up high resistance (if it starts to run). There should also be a relay that controls the operation of the fan, so if you don't have much experience diagnosing electric concerns, replacing it is pretty inexpensive and it will garauntee that the relay won't fail since you just replaced it.

If you do have an ohm meter, measure the relay accross terminals 85 and 86 (stamped on bottom of relay in small numbers) and you should get between i believe 50 to 80 ohms. You can then put a jumper wire to one side from a + battery source, and a - lead to the other side to activate the relay (hear it click) and measure resistance accross the other terminals. One should read 0 ohms resistance, two of those terminals should also read like that without hooking up power to the relay (but these terminals aren't used anyway).