95 Escort Sedan 1.9 Cooling Fan???

[dwbailey]

For some strange reason my cooling fan doesn't kick in until the guage is about 3/4 of the way to H. Any ideas why it is taking so long to come on? Also, the a/c will not stay on. As soon as I turn it on it immediately kicks off. Relay on firewall was checked and is supposedly good. Ideas? Thanks guys.

[denisond3]

The compressor shutting off soon after it turns on is usually a sign its low on freon.
If a check of the system pressure with gauges shows its still fully charged, then likely the orifice tube is clogged up, and the freon is being backed up causing the compressor to shut off due to high pressure. However that is much less likely than the system having lost most/much of its freon. Along with lost freon, its likely to lose some of the lubricant too - so just adding freon may make it work for a while - but lack of lubricant can also damage the compressor moving parts. Such reasons are why I dont bother to fix the a.c. systems when they quit working in the family cars. Good Luck with that.


As for the fan not coming on till the gauge is fairly close to "H" - was it turning on at lower gauge readings in the past, (like last summer)? The gauges arent highly accurate, can vary a good bit from car to car. Ford even made a kit to rectify this, with a new gauge and a new temp sensor. Im not recommending you try to get such a kit from a dealer, but just to illustrate that the gauges arent super accurate. They should be consistent on a given car, from year to year though.
My 92 had a gauge that would read quite high - as long as the engine was running. If I shut the motor off but turned the ignition back on, then it would read in the middle of the word 'normal'. I found the strange little ground connector that has several wires running to it was corroded. Cutting it off and soldering the wires together, then adding another wire that let me ground those several wires to the body of the car solved the problem of the gauge reading high. The regular negative battery cable was grounded to the body at the same point, just behind the battery. This was a problem that appeared little by little until it bothered me enough to go looking for a cause.
The sensor that drives the gauge is the one by the thermostat housing that has only one pin on it, only one wire in its connector. That sensor can age and read high, or corrode and read low, and the connector is not the best either; but could result in the gauge reading 'low'.
A way tell if your car is beginning to overheat, or if the gauge is simply indicating wrongly, would be to get one of those handy infrared temp gauges. When I point mine at the upper radiator hose, it shows about 200 to 205 when the fan kicks on. It shuts off when the hose is showing about 195.
The fan coming on is controlled by a different sensor. Its the one next to the sensor for the gauge, but its a different shape and has two wires to it. This is the engine coolant temp sensor, and it tells the PCM how hot things are. The PCM is supposed to turn the fan on its low speed when the water is about 205f, and on high speed when the water is up to 215 or so. It should also run on high when the a.c. is working, but not if the a.c. compressor shuts off so soon. The Engine Coolant Temp sensor can also age and give the pcm the wrong info.
I suppose its possible the relay to turn your fan on to its low speed is gone bad (their contacts can melt), or that the one set of brushes inside the motor for its low speed operation have worn out. There are 3 brushes inside the motor. One of them is the grounded brush, the other two are for the low speed windings, or the high speed windings. You might be able to check this out by unplugging the cable to the fan, and supplying 12 volts across the contacts. You should be able to make it run on both low and high speeds. There is one fan relay inside the box next to the battery, but the two relays for low speed and high speed control are hidden inside the driver's side fender - only accessible after you take out the air filter housing. They are supposed to be covered by a little rubber 'raincoat'.
The fan should also come on for less than a second when the ignition is first turned on. This is because the PCM actually tells the relay to 'open', once the PCM has done its power on self test. So if the fan doesnt 'jerk' and spin briefly, something isnt right.

[dwbailey]

Originally Posted by denisond3

The compressor shutting off soon after it turns on is usually a sign its low on freon.
If a check of the system pressure with gauges shows its still fully charged, then likely the orifice tube is clogged up, and the freon is being backed up causing the compressor to shut off due to high pressure. However that is much less likely than the system having lost most/much of its freon. Along with lost freon, its likely to lose some of the lubricant too - so just adding freon may make it work for a while - but lack of lubricant can also damage the compressor moving parts. Such reasons are why I dont bother to fix the a.c. systems when they quit working in the family cars. Good Luck with that.


As for the fan not coming on till the gauge is fairly close to "H" - was it turning on at lower gauge readings in the past, (like last summer)? The gauges arent highly accurate, can vary a good bit from car to car. Ford even made a kit to rectify this, with a new gauge and a new temp sensor. Im not recommending you try to get such a kit from a dealer, but just to illustrate that the gauges arent super accurate. They should be consistent on a given car, from year to year though.
My 92 had a gauge that would read quite high - as long as the engine was running. If I shut the motor off but turned the ignition back on, then it would read in the middle of the word 'normal'. I found the strange little ground connector that has several wires running to it was corroded. Cutting it off and soldering the wires together, then adding another wire that let me ground those several wires to the body of the car solved the problem of the gauge reading high. The regular negative battery cable was grounded to the body at the same point, just behind the battery. This was a problem that appeared little by little until it bothered me enough to go looking for a cause.
The sensor that drives the gauge is the one by the thermostat housing that has only one pin on it, only one wire in its connector. That sensor can age and read high, or corrode and read low, and the connector is not the best either; but could result in the gauge reading 'low'.
A way tell if your car is beginning to overheat, or if the gauge is simply indicating wrongly, would be to get one of those handy infrared temp gauges. When I point mine at the upper radiator hose, it shows about 200 to 205 when the fan kicks on. It shuts off when the hose is showing about 195.
The fan coming on is controlled by a different sensor. Its the one next to the sensor for the gauge, but its a different shape and has two wires to it. This is the engine coolant temp sensor, and it tells the PCM how hot things are. The PCM is supposed to turn the fan on its low speed when the water is about 205f, and on high speed when the water is up to 215 or so. It should also run on high when the a.c. is working, but not if the a.c. compressor shuts off so soon. The Engine Coolant Temp sensor can also age and give the pcm the wrong info.
I suppose its possible the relay to turn your fan on to its low speed is gone bad (their contacts can melt), or that the one set of brushes inside the motor for its low speed operation have worn out. There are 3 brushes inside the motor. One of them is the grounded brush, the other two are for the low speed windings, or the high speed windings. You might be able to check this out by unplugging the cable to the fan, and supplying 12 volts across the contacts. You should be able to make it run on both low and high speeds. There is one fan relay inside the box next to the battery, but the two relays for low speed and high speed control are hidden inside the driver's side fender - only accessible after you take out the air filter housing. They are supposed to be covered by a little rubber 'raincoat'.
The fan should also come on for less than a second when the ignition is first turned on. This is because the PCM actually tells the relay to 'open', once the PCM has done its power on self test. So if the fan doesnt 'jerk' and spin briefly, something isnt right.

First of all let me say thank you for the insight and say that you obviously know your stuff. Will address the issues you raises individually.

I had the a/c system checked, not knowing before I did that it came on for an instant then kicked off. It was the mechanic that checked it out and also flushed the rad that told me. He checked the freon and said it was full. The first thing he checked after that was the A/C relay on the firewall. He said it is supposed to be seeing a certain voltage from the PCM and that it was only reading a fraction of that. He put a new relay on it and same thing happened. Shuts off almost immediately after the switch is pushed in the car. He jumped the pins and the a/c came on and stayed on which made him result in the fact that there is either a short in the wires from that relay to the PCM or the circuit in the PCM is bad. Said there is nothing between that relay and the PCM other than wire. I chose to get a PCM off of eBay and installed it. Same thing happened. Comes on and kicks right back off. Put old PCM back in. Taking it back to him next week to have him check something else. What I don't know but something else. If you can suggest anything else I might check out between now and then or suggest he check, that would be appreciated.

Now for the cooling fan not coming on until the guage is 3/4 of the way to H. I don't ever recall it going way over there before. It is my son's car who is 18 so it could have been doing that and he not even notice. I do know that when I bought it, the previous owner had tapped a wire into the one coming off of the fan motor directly into a hot one I suspect so this problem may have been a reason he got rid of it? I rewired that wire back to where it was supposed to go last year but like I say am not sure what that did or didn't do. The guage for the longest time was fluxuating all over the place like there was a short in it and I initially thought it was the connector for the engine coolant temp sensor that you mentioned and when I was checking it out, one of the wires going into it came out. Got a new connector from NAPA and wired it in with those in-line wire lugs. Hope that was OK and didn't impact the readings that it send to the PCM thus causing the high readings and late fan startup. That actually wound up not being the problem at all. The connector for the guage at the sensor was not on tight so when I realized that, I squeezed it a bit so it would stay on that screw pin and the guage has worked fine ever since. I'm just wondering if whatever caused the previous owner to rig up the wiring from the fan is the problem? When the mechanic flushed the rad he was waiting on the cooling fan to go off before he wrapped it up. My son says he thinks he hears it come on but not until it is well on its way to H. only goes that far when sitting still. Get going and the air going across rad I assume makes the guage go back to normal. Said he wondered what that sound was but never said anything. Told him it was probably the fan coming on. Haven't had a chance to corner him long enough to let it sit and run long enough for it to heat up enough for the fan to come on. He is coming over this afternoon and I will check it out. Also gonna see if the mechanic has one of those infrared temp guages. Pretty positive the fan doesn't come on when the ignition is first turned on and never has. Think I would have noticed that but will check when he comes by.

Thanks again for your valuable insight and knowledge. If you can think of anything I should check with the "rest of the story" info I've provided I'd appreciate it.

[denisond3]

If the fan doesnt come on at all when the ign. key is first turned to on, I could suspect that the low fan speed is non-functional. That could explain the temp getting close to "H" before the PCM switched the fan on its high speed. It could be a bad fan motor (they are pricey to buy simply to find this out), or a bad circuit in/around the low speed relay.
Its kind of a strange wire-up. I believe the low speed fan relay has to be turned 'on' by the PCM to -stop- the fan from running on the low speed, and the high speed fan relay has to be turned 'on' by the PCM to make it run at the high speed. If the a.c. system is working right, anytime the a.c. compressor is running (controlled via the PCM, not by hot wiring the compressor clutch), the rad. fan should be on its high speed. If you can get the fan to run using the a.c. system, compare that to the noise you get when you let the engine idle till its hot enough for the fan to come on. There should be a noticeable difference in fan noise, between low speed and high speed.
When turning on the a.c. system, if things are working right, it may be several seconds before the PCM turns the fan on. It may also be several seconds after the a.c. system in turned off before the PCM shuts the fan down.

I bought a replacement rad. fan motor last summer from Autozone ($88) for our 91 Escort. The old motor had eaten its front bearing.. The new one looked like the old one, had three wires, but the installation instructions said that you could hook up either of its power leads to either of the power wires on the existing plug. This was because it was really a one speed fan - just having the extra wire to make connecting easy. I dont know how fast it runs compared to the original fan motor, but it definitely cools the engine well enough; we crossed Arizona and New Mexico in both directions this June, with the a.c. on.
I plan to replace the fan motor on my 92 either this fall or next spring, but will attempt to get a 'real' Escort replacement fan, with a two speed motor.

A number of Escort owners have had failures of the fan relays, including melted connectors to the relays, and have devised ways to rewire things, using the very standard 30 amp single pole due throw 12 volt relays (having 5 pins) sold in auto parts places - for a lot less than the Ford OEM style relays. I plan to do that myself, if and when my fan relays ever get melted.


If your a.c. compressor is okay, you should be able to grasp the end of it and rotate it, with some resistance. (This with the motor shut off of course). As you continue to rotate that part, you should feel the resistance slightly increase, as you pump up a little bit of pressure in the high side of the system.) If its very easy to turn - that isnt good. If its really really stiff, that isnt good either.

[dwbailey]

Pretty sure the fan doesn't come on at all when ignition switch is first turned on. Will confirm when I see my son and provide the info you listed to my mechanic unless I can stumble upon something before next Thursday. It does come on at least when it gets hot enough IF that sound was the fan coming on that he mentioned. Also the mechanic that flushed the rad was waiting on it to go off so that says its not frozen at least. Can't really check anything out on the a/c since it won't come on and stay on more than a second or two.