Yesterday, for the first time ever since I've owned my car (a little over a year), the temp gauge on my '99 SL2 started steadily climbing within a minute's time to the 3/4 mark on the temp gauge while stopped at a red light. When this happened my AC was on and went from cold to hot. I shut off the AC the light turned green.. by the time I was home the temp gauge had gone down to the 1/2 mark.

After reading other similar posts I just need some help pinpointing the problem. Could it be just simply the ECTS? or the fan fuse, relay, or the fan motor? Or something else?

Also, does anyone know where I could find diagrams online for all these parts and their locations in the car? When I bought my car the seller didnt have the manual.


If anyone could help it would be greatly appreciated.

 

Well, obviously, the first thing I'd do would be check the fluid level in the radiator. Assuming to be good, next thing would be to set the A/C for maximum cooling and recirculate the inside air. Start the engine, and check to see if the radiator fan is running. I'd also check the fan fuse, fan relay, and the electrical connections associated with these parts. Let us know what you find ............

 

The fluid is at the right level. With the A/C on max with air recirculating, as far as I can tell, the radiator fan is NOT running. I went to my local Auto Zone thinking they would be able to use a power meter and jumpers to check the fan relay to make sure the fan is getting power (because I don't have that kind of testing equipment)... Long story short they were no help. They treated me like I was an idiot and said they don't do that kind of service for people, also they didn't have the relay for my car in stock.. back to square one. Meanwhile my car was overheating in the parking lot, once I got on the highway to go home the air rushing into the radiator cooled it down. I'm almost positive it's the fan, just not sure which component. I'm gonna have to take it to a shop since I don't have the equipment to test it. First I'll try replacing the relay. If that doesnt do it, it has to be the fan motor or connections.

Do you think since my instrument panel temperature gauge is responsive to the changes in coolant temp that I can rule out the problem being the ECTS?

Thanks for your help! I've been reading all your previous posts on other people's threads about similar problems. It's been extremely helpful in understanding what's going on.

 

A quick and dirty observation is this. When you turn on your A/C the fan should run. It is part of how things are designed. If it is not running then the odds are very high it willl not run under any circumstance.
It does not fix anything, but does assure you the fan is the culprit.
Your approach is logical! To tell the truth, I have found relays and things at a local pick-a-part junk yard is not a bad way to get stock and spare parts.
Your treatment at Auto Zone is not really out of line. The counter men or ladies are usually barely able to read the computor screen for parts look up. That is all they realy have to do. However there are many good people that work there too. Just hard to find them.
For the relay? I have had good luck with Carquest and NAPA for parts I did not think I could buy at auto parts stores.
The seem to stock a more proffesional line of parts or have a more proffesional line of counter people.
If you can't deal with a pick A part junk yard check with a local GM dealer and ask if any one locally can get Saturn Parts. Since Saturn is in the final stages of going Belly Up the load is being picked up by select GM dealers as far as being able to order and buy parts.
As far as test equipment. Harbor freight has a perfectly good DVM (Digital Volt Meter) that they sell on sale for $2.00 and any day of the week for $6.00 and will do almost anything an expensive meter does. I have 2 or 3 of them plus a $400.00 DVM.
With all the electronics in todays cars and the need to understand them as they, we and technology all get older is getting more important as time passes.
Harbor Freight has local stores where I live but it also has an extensive on line catalog sales.

 

Thanks so much for all the info. I called a GM dealer in my area. They have the parts I need. Hopefully replacing the motor should do the trick. On second look at the fan, it is spinning just extremely slow with a burning smell. So that leads me to believe the motor is the culprit! I appreciate all your help Ocean Archer and UnclJohn. I know so much more about my car than I used to.

 

It is not difficult to change the fan out, I have a couple of them but it would not hurt to purchase a repair manual for your car. It is cheap insurance in being able to make a repair with out making and expensive mistake.
An auto parts store such as O'Reilly or Autozone usually has these available. About $20.00 bucks.

 

Yup -- your fan has made it's last trip .........

 

my 1999 sc2 overheated today while stuck in traffic, steam from hood and water under car but gauge never went past 1/4 on the gauge?? does this sound like the ects? I will check the fan after work to see if it is working or not. Thanks for any help.

 

I just went out and checked my oil and it actually looks like oil and not chocolate milk and when I turned on the a.c. the fan came on right away. could I have a bad temp sensor or thermostat?? Thanks for any help.

 

Sounds like thermostat stuck closed. The ects drives the meter on the dash as well as the reading the PCM infers from its resistance. The temp only went up to 1/4 b c the thermostat stuck closed, thereby not allowing coolant to freely circulate throughout the engine

Remember that the ects is a temperature indication at.a single physical location. In the head. If the coolant isn't circulating, the reading is not indicative of the temp of the entire system. As a result, the rest of the system overpressurizes, the reservoir cap releases pressure around 15 psi, and you overheat.