erratic idle

[davo55]

2001 Tundra 4x4 V8 automatic trans. Concern: When and only when I have the interior fan running and I'm waiting at a stop light in gear, I hear a low click from behind the dash by the glove box and the engine idle increases enough so that I have to apply a bit more pressure on the brake to keep still. Then, a minute or less later, the same click happens and then it idles back down to normal. The air conditioning is not on. Any ideas? worth taking in to get looked at on Warranty?
thanks
Dave

[Jimbo]

The engine management computer is raising the idle on your engine, that much is certain. The idle should not be raised by the computer when fan/climate control system is off.

With your comment that AC is off, perhaps you have selected defrost, in that case AC compressor is usually turned on - even when you don't push the AC button.

Maybe your AC on light is broken, or the button/switch for AC is stuck ON even with it appearing to be OFF.

Jimbo

[tonyp]

If the climate control switch is in defrost or floor/defrost, the a/c compressor WILL run. That will cause and increase in enginr idle speed and you will have to press harder on the brake. Is your climate control selector switch in either one of thede positions???

[SATundra]

Classic symptons of the A/C compressor kicking on/off. Odds are you have the selector in one of the settings noted below. If so its normal. You will get used to it and compensate for it.

[davo55]

Originally posted by tonyp
If the climate control switch is in defrost or floor/defrost, the a/c compressor WILL run. That will cause and increase in enginr idle speed and you will have to press harder on the brake. Is your climate control selector switch in either one of thede positions???

Why, yes it is as a matter of fact. That pretty well answers my question.
thanks
Dave