cooling fans
#11
08-14-2006, 04:00 AM
RE: cooling fans
Thanx for your input 4x4. I will dicker with this thing for another week and see what I come up with. The problem is that it's my wife's car and I've been driving it more because my truck loves gas. Maybe what I'm seeing has always been. I don't know. I'll get back.
#13
08-15-2006, 05:38 AM
RE: cooling fans
I appreciate the input but in my first post you'll notice that I tried another PCM. I think I am going to clean in between the rad and condenser and see what happens. I'll be back. Thanx
#14
08-24-2006, 02:25 AM
RE: cooling fans
Still looking for someone out there that has had a 96 Taurus where the cooling fans turn on and off with AC on and did they discover what the problem was. Been doing a lot of reading and cannot find this problemhappening with anyone. Also on the 96 are these 2 speed fans? Thanx
#15
08-25-2006, 05:35 AM
RE: cooling fans
I don't know how different '95s are, but I've recently been battling a similar situation. Except, the fan (single fan) won't come on at all, even with the a/c on, once the outside temp gets into the upper 90's. When the outside temp is cooler, things work fine. With numerous recent days over 100, this has been a real problem. Here's what I found and subsequently did.
The cooling fan is energized by a 'relay control module'. The ECM allows the fan relay(s) to energize based on a 'signal' via a single wire bewteen the ECM and relay module. The temperature sensor tells the ECM the temperature of the coolant, and the ECM causes the fan to energize based on the temp and the state of the a/c.
I obtained a simple wiring diagram (from www.autozone.com for the specific car), and was able to determine several places for which to check for voltage. You need to know where the problem really lies: is the relay module getting controlled from the ECM? Is there proper voltage at the relay module? Is the relay module energigining but the fan not engaging? Is there a wiring problem?
Ideally, you want to check voltages and operation when the car properly works, so you know what it is supposed to do. This will let you isolate or rule out any wiring issues as well.
Anyway, what was happening on my Taurus was that during proper operation, the control wire from the ECM (I think it was tan/orange in color) was at 8 volts when the fan was on, 0 volts when the fan was off. A person would would probably think that you'd simply beed to give that wire 8-12 volts from a hot circuit and the fan nwould work. NOT! As it turns out, when I cut the wire between the ECM and relay module, the relay module internally raises the circuit to 8 volts and turns on the fan. The ECM therefore serves to act as a solid state 'switch to ground' to turn off the fans by getting the voltage to 0, or opening and letting the control module voltage rise and (via transistor swithing inside itself) switch on the fan relays.
So, I simply put a switch in series with the wire I cut, to connect or disconnect the wire between the control module and ECM. Leaving the switch open will cause the fan to always stay on, regardless. When I want the ECM to control the relay module again, I'll simply close the switch; this will be needed once cooler weather arises.
While this approach is not good for the fan because it stays on more than it really should, it solves all overheating.
Idelly in this case, the proper fix would be to replace the ECM, since the relay control circuit is malfunctioning. But since all other aspects of the ECM appear to be working, usiing a switch in this circuit was a viable alternative.
Hope this helps.
Mike
'95 Taurus GL
'98 Contour
'05 Mustang V6
The cooling fan is energized by a 'relay control module'. The ECM allows the fan relay(s) to energize based on a 'signal' via a single wire bewteen the ECM and relay module. The temperature sensor tells the ECM the temperature of the coolant, and the ECM causes the fan to energize based on the temp and the state of the a/c.
I obtained a simple wiring diagram (from www.autozone.com for the specific car), and was able to determine several places for which to check for voltage. You need to know where the problem really lies: is the relay module getting controlled from the ECM? Is there proper voltage at the relay module? Is the relay module energigining but the fan not engaging? Is there a wiring problem?
Ideally, you want to check voltages and operation when the car properly works, so you know what it is supposed to do. This will let you isolate or rule out any wiring issues as well.
Anyway, what was happening on my Taurus was that during proper operation, the control wire from the ECM (I think it was tan/orange in color) was at 8 volts when the fan was on, 0 volts when the fan was off. A person would would probably think that you'd simply beed to give that wire 8-12 volts from a hot circuit and the fan nwould work. NOT! As it turns out, when I cut the wire between the ECM and relay module, the relay module internally raises the circuit to 8 volts and turns on the fan. The ECM therefore serves to act as a solid state 'switch to ground' to turn off the fans by getting the voltage to 0, or opening and letting the control module voltage rise and (via transistor swithing inside itself) switch on the fan relays.
So, I simply put a switch in series with the wire I cut, to connect or disconnect the wire between the control module and ECM. Leaving the switch open will cause the fan to always stay on, regardless. When I want the ECM to control the relay module again, I'll simply close the switch; this will be needed once cooler weather arises.
While this approach is not good for the fan because it stays on more than it really should, it solves all overheating.
Idelly in this case, the proper fix would be to replace the ECM, since the relay control circuit is malfunctioning. But since all other aspects of the ECM appear to be working, usiing a switch in this circuit was a viable alternative.
Hope this helps.
Mike
'95 Taurus GL
'98 Contour
'05 Mustang V6
Thread
Thread Starter
Forum
Replies
Last Post
