Cold AC at Idle, but outlet temp warms while driving
Thread Starter
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
Cold AC at Idle, but outlet temp warms while driving
I can't find anything on this subject. My 2002 climate control AC today is blowing cold at idle, but warms up while driving. First time I ever noticed this. Its about 78° sunny today, very low humidity. It's almost like the belt is slipping while driving not engaging the clutch. But come to a stop light and it's cold again. There is no belt burning smell, there is no squeeling noise. Could it be low on Freon? Any other thoughts? Thank you.
Thread Starter
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
TY, does the hvac have its own set of codes you can read from the AC LED? Otherwise I can't pull any codes, at all.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,657
Likes: 4,090
From: Cape Coral, Florida
No the AC LED won’t tell you what codes there are…HVAC codes are either “P” (Powertrain) or “B” (Body)…you can access these codes using the DIC…video below if you’ve never done it…also HVAC codes do not illuminate the check engine light.
Last edited by C5 Diag; Mar 24, 2023 at 06:36 PM.
Thread Starter
Burning Brakes
Joined: Jun 2018
Posts: 756
Likes: 172
From: SC
I'm reasonably sure the AC belt was slipping the other day. Today I started and let idol for a few minutes to stabilize and the pressure looks fine. At start up I noticed some chirping from that belt area that went away as it warmed up. The other day I started and went, no warm up and probably hit the gas as I turned onto the main road. If it is slipping I'm thinking punching it at high revs may have slicked the belt while it was cold. Today I atarted and idled for 5 minutes or so, then reved up, drove and punched it, cold throughout.
