New ECTS, new thermostat, A/C works, NO FAN WHILE DRIVING

[MrMooseisLoose]

So I've been reading up on all the posts about the S-series cooling fan problems, cause I have one now and I'm in need of some guidance because I've done everything that I can think of so far.

HISTORY: 98 Saturn Wagon DOHC-106,000 miles-5-speed-with A/C that was recharged 2 months ago and was working fine since.

Recently I changed oil and filter, changed the $100 fuel filter/pressure regulater, plugs, flushed cooling system, installed new radiator (old one cracked where they all do), thermostat, and replaced the ECTS to get the gauge working right and get the car to idle correctly. The car was running great except for a slight accelerator "bog down" problem that I was noticing, that I posted about here a couple of weeks ago and got some advise to check out/ clean my EGR valve. I agreed with that, ordered the EGR gasket, and WAS going to be doing that today....................until this happened.

Before I go on let me say that I've read quite a few posts about people saying how It's normal to have your temp gauge go up 3/4 of the way, or even into the red before the fan kicks on. I'm sorry, but that's just rediculous. If your car is doing that, you need to fix it. Letting the engine cycle up to those temps and back down all the time is only going to cause you more problems in the future, and give you less engine life.

So my temp gauge has always worked "normally", in that when the temp started to climb just a small amount above it's normal spot of "a little over 1/4", going up to maybe about 1/2, the fan would kick on. Just 2 weeks ago, while in a parking lot with the motor warmed up but not hot, I had verified that the fan kicked on with the push of the A/C button. I had recently had the A/C recharged and wanted to verify that it still functioned properly. It checked out good.

Well, yesterday while doing things around town, I was sitting at a red light and noticed my gauge climbing, and climbing, and climbing. When I popped the hood and checked the fan, it was not working. Pushing the A/C switch didn't do anything either, and my A/C compressor won't come on. I don't know if the fan problem is preventing the A/C compressor from working, just like a low A/C charge will prevent the compressor from coming on.

So today, so far, I have pulled the fan out and put 12 volts to it directly and it works. I then put it back in, left the plug to it undone, hooked up my voltmeter to it and fired it up to see if I got juice to it when the motor started to get too hot. I couldn't get the temp gauge to go over the normal mark of "a little above 1/4", so I went on to something else. I tried to turn on the fan with the A/C button again and it still didn't come on. I pulled the A/C and cooling fan relays and switched them, still nothing.

Next I pulled the connecters off of the ETCS, (and the ATS while I was at it) to verify that the connecters had about 5 volts with the key on, motor not running. That checked out good. Next, after a nap, when the motor was cool, I checked the OHMS resistance of the ETCS and ATS. With the OHM meter set on 20K, I got readings of 2.70 and 1.98, so that checks good too. According to my Chiltons manual chart, those readings put the sensors at about 80-90 degrees with the motor cooled, and it is about 75 degrees outside temp.

So now I don't know what to do next. HEEEEEEELPPP!!!

Thanks,
MrMoose

[Chriscnl]

I would say check again to see if your AC freon did not leak out.

[madpogue]

What do you mean by "ATS"?

To test the A/C, find the refrigerant line along the left fender, by the battery. There's an electrical connector going into the line. That's a pressure switch. Disconnect it and jumper the connector. Start the engine and BRIEFLY run the A/C. If the compressor kicks in and the fan comes on, then either that switch is falsely reading insufficient pressure, or indeed you've lost refrigerant pressure. If the compressor kicks in but the fan still doesn't come on, you've got some other fan electrical issue (switch the fan relay with something OTHER than the A/C relay).

[MrMooseisLoose]

Originally Posted by madpogue

What do you mean by "ATS"?

To test the A/C, find the refrigerant line along the left fender, by the battery. There's an electrical connector going into the line. That's a pressure switch. Disconnect it and jumper the connector. Start the engine and BRIEFLY run the A/C. If the compressor kicks in and the fan comes on, then either that switch is falsely reading insufficient pressure, or indeed you've lost refrigerant pressure. If the compressor kicks in but the fan still doesn't come on, you've got some other fan electrical issue (switch the fan relay with something OTHER than the A/C relay).

ATS= Air Temp Sender. It's the exact same sender as the CTS (Coolant Temp Sender) and it sits in the mouth of my air filter box intake tube.

I did think about the possibility of lost A/C refrigerant again............but I was really hoping that that was not the case, and I didn't really know how to check it. Thanks for the "how to" steps.

But when I do that, like you said, if it comes on I still won't have solved my problem. I won't know if the switch is falsly reading low pressure, or if I indeed have lost all my A/C charge..........again.

And isn't it correct to say that whether or not the A/C system is working, my cooling system for the motor temp should be working? I mean my wife and I drove around with the A/C charge gone for over a year and the fan still worked then. They have to be separate systems right?

As for switching the relay with another relay other than the A/C relay, which one do I use? I only have those 2 in the fuse box under the hood.

Thanks again,
MrMoose

[eljefino]

You didn't let the car idle long enough to test the temp-related fan engagement. It is one relay controlled by the PCM; in fact, the PCM also "demands" A/C then checks to see if the clutch really did engage. The button on your dash climate controls just tells the computer you want AC. So the fan relay output is one circuit, one relay, etc.

As you warm the car up you'll hit a plateau when the thermostat starts to open and all the cold radiator water has to get warmed up too. The gauge will stick in the middle, normal, range, for many minutes as the radiatior coolant gets warmed up too. To continue this diagnostic, one really needs to burn more gas and let it get hotter.

You need a still, ie not windy, day to do this, as a stiff breeze blowing through your rad will negate the need for a fan.

The gauge is somewhat alarmist and miscalibrated but OTOH the engine doesn't know a three cent gauge pointer is pointing at a red spot on a two dollar gauge. Normal equals Normal operation.

[fdryer]

Originally Posted by MrMooseisLoose

And isn't it correct to say that whether or not the A/C system is working, my cooling system for the motor temp should be working? I mean my wife and I drove around with the A/C charge gone for over a year and the fan still worked then. They have to be separate systems right?

As for switching the relay with another relay other than the A/C relay, which one do I use? I only have those 2 in the fuse box under the hood.

Thanks again,
MrMoose

As confusing as things are, did you plug the fan harness back in? Have to ask the mundane question as you have two(2) separate issues, both requiring the radiator fan to operate at different times. Not having a/c for a year and then having it again after a quickie recharge spells an incomplete diagnosis of the a/c system; there's a leak somewhere, plain and simple preventing proper a/c and fan operation that will confuse this situation. The fact that you have to bypass the a/c pressure switch to get the fan to come on indicates a leak occurred already and complicates your situation of resolving a radiator fan problem. The a/c and engine cooling system are separate as you assume. The fan does double duty cooling both a/c and radiator simultaneously. Turning on the a/c is a surefire test for fan operation as long as the a/c system was working properly. You've described a recent a/c repair that may have leaked out refrigerant, stopped the fan from powering up immediately, possibly giving false symptoms.

By taking the advice of temporarily bypassing the a/c pressure switch and turning on the a/c will allow power to the radiator fan. Do this and have the fan harness accessible so you can read the output; engine running, a/c on, there should be 12volts at the harness supplying power to the fan. The absence of voltage at the wires suggests a fuse, relay, or wire problem. Even though the fan worked by direct power it may be on its last legs as the fan brushes will wear out and give false indications of working for now until it fails next time in the car. That's assuming you've checked the power going to the fan and power is available to run the fan. Hope this hasn't confused you.

BTW, by bypassing the a/c pressure switch you won't have to have the engine up to operating temperature to get the fan to come on.

[MrMooseisLoose]

Originally Posted by fdryer

As confusing as things are, did you plug the fan harness back in? Have to ask the mundane question as you have two(2) separate issues, both requiring the radiator fan to operate at different times.

LOL. I knew as I was typing my last post, that someone that is paying close attention would catch that. Yes, I did check it with the plug in. Actually, I just typed my paragraph a little out of chronological order. I didn't have to plug it back in because I did that test before I unplugged it. But good on you for catching that!

Not having a/c for a year and then having it again after a quickie recharge spells an incomplete diagnosis of the a/c system; there's a leak somewhere, plain and simple

Yea, I was thinking the same thing.............but having a hard time accepting it. It's $117 out the window unless I can convince the guy to be honest, come back, and pressure check it right the first time.

preventing proper a/c and fan operation that will confuse this situation. The fact that you have to bypass the a/c pressure switch to get the fan to come on indicates a leak occurred already and complicates your situation of resolving a radiator fan problem. The a/c and engine cooling system are separate as you assume. The fan does double duty cooling both a/c and radiator simultaneously. Turning on the a/c is a surefire test for fan operation as long as the a/c system was working properly. You've described a recent a/c repair that may have leaked out refrigerant, stopped the fan from powering up immediately, possibly giving false symptoms.

By taking the advice of temporarily bypassing the a/c pressure switch and turning on the a/c will allow power to the radiator fan. Do this and have the fan harness accessible so you can read the output; engine running, a/c on, there should be 12volts at the harness supplying power to the fan. The absence of voltage at the wires suggests a fuse, relay, or wire problem. Even though the fan worked by direct power it may be on its last legs as the fan brushes will wear out and give false indications of working for now until it fails next time in the car. That's assuming you've checked the power going to the fan and power is available to run the fan. Hope this hasn't confused you.

BTW, by bypassing the a/c pressure switch you won't have to have the engine up to operating temperature to get the fan to come on.

All good info for sure. Thanks man. I will have to wait for a day this week when I get home from work early enough to dive into the motor again and try what you suggest. I will report back as soon as I find out the results. BTW I did have a "still day" and thought of that as well. I was actually in the car trying to think of ways to make it run hotter, faster.

I am having a hard time believing that the A/C charge leaked out at the same time that the fan quit working. Sure it could happen, but it's odd. Of course now that I think about it, my wife has been driving the car mostly lately, and she hardly ever uses the A/C. So maybe it did in fact leak down low enough a week ago or so, and only now am I finding out all of this.

MrMoose

[MrMooseisLoose]

Originally Posted by eljefino

You didn't let the car idle long enough to test the temp-related fan engagement. It is one relay controlled by the PCM; in fact, the PCM also "demands" A/C then checks to see if the clutch really did engage. The button on your dash climate controls just tells the computer you want AC. So the fan relay output is one circuit, one relay, etc.

As you warm the car up you'll hit a plateau when the thermostat starts to open and all the cold radiator water has to get warmed up too. The gauge will stick in the middle, normal, range, for many minutes as the radiatior coolant gets warmed up too. To continue this diagnostic, one really needs to burn more gas and let it get hotter.

You need a still, ie not windy, day to do this, as a stiff breeze blowing through your rad will negate the need for a fan.

The gauge is somewhat alarmist and miscalibrated but OTOH the engine doesn't know a three cent gauge pointer is pointing at a red spot on a two dollar gauge. Normal equals Normal operation.

Well I watched that temp gauge go up ever so slowly, then hit the plateau at it's "normal" temp reading, then climb just a tiny bit more, then, then, it just sat there. The car idled for a good 15 minutes. Should I go 30? That's not good for the catyletic converter. Maybe I should just drive the stupid thing hard for 10 minutes, then come home and park it in the sun with plastic covering the front of the car. That should do it eh?
Thanks for the info. Guess I'll have to try it again.
MrMoose

[MrMooseisLoose]

Well I finally got some time this last Saturday to work on my fan problem again. I "downed" the car for the week till I could test some things again, so it just sat.

Besides leaving the A/C and Fan relays where they were after switching them last week, I put back all the parts that I had taken off and left the fan wire unplugged.

I jumped in the car, warmed it up a bit, took it down the road 5 miles to a coffee shop, popped the hood, hooked up my volt meter to the fan plug and left it running while I went in for some java and chat. I checked the temp gauge and the volt meter every 5 minutes or so. After about 20 minutes, the temp gauge read just a tad over half and the volt meter finally gave me a reading of 14.36 volts. That surprised me. I shut it off and let it cool for 10 minutes, hooked the fan wires back up, and drove it home again. I left it running in the driveway for about 10-15 more minutes until I heard the fan kick on.

Soooooooo, the stupid thing WORKS again.

I don't know exactly what happened, but I'm happy for now. This weekend I will check the A/C to see if the fan works with that system, and try to determine if my A/C charge has in fact leaked out again. I'll also finallyi dive into taking off the EGR valve, cleaning it, and remounting it to see if it drives without the throttle problem that I have been having.

Thanks again for the info guys.
MrMoose