Cooling fan issue with my dd car
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Cooling fan issue with my dd car
My car is a 1999 Escort zx2. Starting this morning the e gine cooling will not shut off with the key. It ran 10 minutes before I just pulled the relay to go into work.
I swapped another relay and it came on with no key.
It is full of coolant, no leaks. The temp gauge reads normal against the torque pro app with 194* reported so not overheating.
If the temp sensor fails, wont the temperature reading go to 0* or 999*. Its reading nomal.
changed relay, so I eliminated the sticky relay.
Scanned for engine light with Torque Pro and nothing came up, light is not on.
I had an issue with the ccrm when I bought the car in 2004. The circuit for the AC compressor opened on the ccrm and the compressor had no power.
now the fan has power on all the time. i replaced the fan motor with a nos Motorcraft anout 4 years ago because of excessive current draw when coming on.
time.faulty temp sensor that reads temp to the obd2 port?
Bad ignition switch?
Ideas????
I swapped another relay and it came on with no key.
It is full of coolant, no leaks. The temp gauge reads normal against the torque pro app with 194* reported so not overheating.
If the temp sensor fails, wont the temperature reading go to 0* or 999*. Its reading nomal.
changed relay, so I eliminated the sticky relay.
Scanned for engine light with Torque Pro and nothing came up, light is not on.
I had an issue with the ccrm when I bought the car in 2004. The circuit for the AC compressor opened on the ccrm and the compressor had no power.
now the fan has power on all the time. i replaced the fan motor with a nos Motorcraft anout 4 years ago because of excessive current draw when coming on.
time.faulty temp sensor that reads temp to the obd2 port?
Bad ignition switch?
Ideas????
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From: Virginia
You said the software said the temp was ok, so not the temp sensor.
Not sure what a CCRM is, but it sounds like some sort of control box. Is it a box that takes care of the heavy duty switching, and is told by the ECM what to do? It could have a shorted circuit inside it telling the relay to come on all the time.
If you put a scanner on it, you may be able to see some of this circuit, and see if the relay is commanded to come on or not. And you should be able to command the fan on or off at will with the scanner. I have never tried it, but they say Forscan is pretty good. It's free and just requires a $30 cable and a laptop.
Not sure what a CCRM is, but it sounds like some sort of control box. Is it a box that takes care of the heavy duty switching, and is told by the ECM what to do? It could have a shorted circuit inside it telling the relay to come on all the time.
If you put a scanner on it, you may be able to see some of this circuit, and see if the relay is commanded to come on or not. And you should be able to command the fan on or off at will with the scanner. I have never tried it, but they say Forscan is pretty good. It's free and just requires a $30 cable and a laptop.
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The CCRM is failure prone. I've seen things fail and quite working. I've never seen a ccrm failure the provides constant power even off.
it is responsible for heavy duty switching. Its a constant control relay module.
when it failed after I bought the car, it cut power to the AC compressor. Ford dealers said the compressor was bad. It was not. It was the CCRM. They wanted $2100 just for the part back then. Now, you can't even find them.
it is responsible for heavy duty switching. Its a constant control relay module.
when it failed after I bought the car, it cut power to the AC compressor. Ford dealers said the compressor was bad. It was not. It was the CCRM. They wanted $2100 just for the part back then. Now, you can't even find them.
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From: Virginia
If what you have is in this link, https://lmr.com/products/what-is-a-m...-control-relay I see relays soldered onto the circuit board. So I certainly could see a relay contact welded together causing the fans to stay on. If you can get it open and are handy at soldering, I bet you could find those relays and change them out. First thing you could probably do is take a meter and do some testing on the board with the meter set on ohms.
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Thank you! I just diagnosed and ordered two NOS Ford relays.
the second one I put in was also sketchy.
i pulled the relay out and tested the conacts, put the relay back in and fan stays off...but cycles normally when ac is on or temps require it.
i will keep an eye on it until my new relays arrive
the second one I put in was also sketchy.
i pulled the relay out and tested the conacts, put the relay back in and fan stays off...but cycles normally when ac is on or temps require it.
i will keep an eye on it until my new relays arrive
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From: Virginia
Sticking on is a failure mode for relays. The contacts get burnt and when they come together they start sizzling and they will weld themselves together. What doesn't help is when the relay contact is supplying power to another coil of some kind. Like the A/C clutch coil or a fan motor.
When you supply power to a coil, it acts somewhat like a capacitor. The power in the coil develops a magnetic field which makes the clutch or whatever it is operate. Problem is when the power is removed, this magnetic field collapses, and sends a high voltage spike back through the system. That will create a spark on the relay contacts and over time they can get burnt.
The common fix for the backward EMF (voltage) is to put a diode across the coil. Ford did this on some of their vehicles, and others they didn't. I suppose they figured the relay would last long enough for the life of the car or truck. But of course they did not expect their car or truck to be on the road over 20 years later.
When you supply power to a coil, it acts somewhat like a capacitor. The power in the coil develops a magnetic field which makes the clutch or whatever it is operate. Problem is when the power is removed, this magnetic field collapses, and sends a high voltage spike back through the system. That will create a spark on the relay contacts and over time they can get burnt.
The common fix for the backward EMF (voltage) is to put a diode across the coil. Ford did this on some of their vehicles, and others they didn't. I suppose they figured the relay would last long enough for the life of the car or truck. But of course they did not expect their car or truck to be on the road over 20 years later.
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