ksvette74

ok, my external temp always reads way low when it is hot for the first 10 minutes or so (about 25 or 30 degrees). It also seems the AC sucks during this, and them improves when the external temp reads correct. My question is this, does the ac use the external temp to decide how much to cool the air? Are the two connected in any way? Also, is this just how it is, or will changing the temp sensor fix it. if a change is needed, where is it and how do I do it?

ZR1991

I am not absolutely sure about the C5, but the C4 hadthe outside temp sensor in the front bumper area. It is likely that it would read lower in some circumstances because of the "shade". But it generally was very accurate as the car moved. The sensor on the dash read the heat load created by the sun, and that fed into the A/C, and it [laded a bigger role, as explained below.

The biggest issue in a hot car is to get the hot air out, so the A/C can work better. Do this by lowering windows, and NOT setting the A/C to max, or recirculating, since that makes it have to cool the much hotter air in the car. Once the air has been exchanged for cooler (but still hot) air from the outside, then the A/C will work better in the max mode if you wish, because it is recooling the same air repeatedly. Some computerized A/C systems are better operated manually during the first 10-15 minutes, especially in the deep South.

But to answer your answer directly, I don't think the outside temp sensor has a factor in how the A/C works, even the computerized ones. The dash indicator is much more important, because it knows the temp inside the car, and whether the car is in the sun or not. So the outside sensor may be used for comparisons, but that is probably about it.

THat is what I think.

tstar

Yes... The HVAC will not allow the AC to come in if the outside temp is at or below 36 degrees, Hmmm I better recant that, I THINK it's 36 degrees, going from memory. But regardless that's what's going on, while your temp sesor is reading abnormally low it's not allowing the AC to come on... Replace the sensor.

Virtual Geezer

It sounds you need a new Ambient Air Temperature Sensor. Check out this link. (The sensor costs less than $20.)

http://forums.corvetteforum.com/c5-t...re-sensor.html

and this one for a pic of the unit and price:

http://www.amazon.com/1997-2004-Corv.../dp/B000FZVW84

Lenrock

I had the same problem with mine a year ago. I cleaned the contacts and it still did it so I went to my chevrolet dealer and the part cost $10.75 and took literally 2 minutes to replace.

Vetteman Jack

The A/C does work in conjunction with the outside air temp sensor.

jedblanks

And it's in the bumper. Pretend you are trying to replace the front passenger fog light or trying to remove the radiator shroud for CAI install, and you'll find it. I think it's connected to the same harness as the hood light but not positive.

Your bumper isn't parked in a freezer is it? Otherwise it's probably a dirty contact. It's possible that it's not working at all and after some time the interior temp sensor or sun load sensor takes over and the AC comes on cold.

ksvette74

Thanks! sounds like I have a project (to go along with my many others.......) It just seems that when the thing says 65 when it is 90 out (today), it does not get the air as cold. When it read the correct, it seems to get it a lot colder.

I will also try the window thing. I have worked hard to make the car cooler by tinting everything I legally could, as much as I legally could.