Taurus Car Club of America : Ford Taurus Forum banner

AC Fan Slows & Less Cool When Car is Idling

6K views 9 replies 5 participants last post by  chartmaker 
#1 · (Edited)
I have a 2000 Taurus 3.0 Duratec DOHC motor and I believe idle speed should be 800 RPM.

When the motor warms up, the idle drops to 700 -750 RPM. When I am driving the car, the air coming out of the vents is cold, but when I stop and the car is idling the AC blower motor slows down and the temperature coming out of the vents is cool but not cold.

When the car is sitting still and idling, if I hold the throttle down and increase the idle to about 800-1000 RPMs, the AC fan speed increases and the cooling temperature increases to cold.

I know the motors are computer controlled but if there was a way to make the idle stay at 800 RPM after the engine is warmed up the AC would always remain cold.

Could it be the Idle Air Control? If so, can they be cleaned or do they have to be replaced?

Any suggestions or recommendations will be appreciated.

Thanks a lot,
Gary
 
See less See more
#6 ·
I will try to locate the IAC and clean it. I don't know what the output of the alternator is because the parts store and my mechanic didn't tell me. I have an analog multi-meter if you can determine the output with it.

Thanks,
Gary



7-800 RPM is the standard warm idle of a Tec. The IAC should kick it up under load from the a/c as needed, there are threads here on cleaning the IAC and that's certainly worth a look. The alternator may be a little tired, what are you seeing for voltage under load?
 
#4 · (Edited)
Thanks for the info....

The AC was charged last week.

Not sure about alternator...O'Riley's Auto parts checked alternator and said the diodes were bad.

My mechanic said O'Riley's didn't have right equipment to test correctly. My mechanic said the alternator was good??
Now I don't know what to believe...

Could the idle air control valve have anything to do with it.

If 700-750 RPM is std warm idle, something is causing the speed of the AC fan to slow down and the AC to lose it's cold air.

Thanks
 
#8 ·
Thanks for the info....

The AC was charged last week.

Not sure about alternator...O'Riley's Auto parts checked alternator and said the diodes were bad.

My mechanic said O'Riley's didn't have right equipment to test correctly. My mechanic said the alternator was good??
Now I don't know what to believe...

Could the idle air control valve have anything to do with it.

If 700-750 RPM is std warm idle, something is causing the speed of the AC fan to slow down and the AC to lose it's cold air.

Thanks
Do the easy tests yourself. You need a digital VOM. As in the pic, you do not need more than ~$10 unit and can clip it to the battery. I use a bit more but no more info, just what I have.

With maximum elect load you should have more than break even = ~12.6V or what your battery is with the engine off and resting .

If not, check the belt, then the Alt is weak. Bad/loose belt usually shows as PS loss under parking with max elect load. A diode fail will cause a partial loss of output, sometimes makes it whine.

My pic is my reference for my 2 Sables, both DOHC but Vulcan should be similar.

-chart-
 

Attachments

#5 ·
7-800 RPM is the standard warm idle of a Tec. The IAC should kick it up under load from the a/c as needed, there are threads here on cleaning the IAC and that's certainly worth a look. The alternator may be a little tired, what are you seeing for voltage under load?
 
#9 ·
Great...thanks to everyone for all of the information. I'll clean the IAC and check the alt output as described.

Hey Chart....you won't believe this, but I finally got the shift indicator in last week and it works great.


Thanks,
Gary
 
#10 ·
Great...thanks to everyone for all of the information. I'll clean the IAC and check the alt output as described.

Hey Chart....you won't believe this, but I finally got the shift indicator in last week and it works great.


Thanks,
Gary
Good job. At least Bulls had a shift indicator. Son's Chrysler had nothing by the shifter, no label period. Same for wife's friend Corolla with nothing by the shifter. And, the cruise lever has only arrows, and the off/on switch has a label not visible to the driver. And a clock only visible to the back seat. Original Bull G-1 design based on logical layout, good labels, tested by real drivers. And as a side: have to give the Corolla designers a finger for the 150 mph speedo.

-chart-
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top