C4 A/C Problems
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
What year car is it?
Do you have a manual or C68 climate control system?
When you turn on the A/C does the blower fan blow air?
Have you checked the fuses?
When you short out pressure switch does it blow cold air, or do any of the pipes (out of top of evaporator) get real cold in 30 – 60 seconds. If so the freon might be OK and there some sort of electrical problem. In that case it could be low pressure switch, relay ECM/PCM or control panel.
If the pipes did not get cold then it might need freon but it has to get pretty low for the switch not to kick in. As set of gauges would definitely be helpful.
With out more information its hard to know where to go.
Do you have a manual or C68 climate control system?
When you turn on the A/C does the blower fan blow air?
Have you checked the fuses?
When you short out pressure switch does it blow cold air, or do any of the pipes (out of top of evaporator) get real cold in 30 – 60 seconds. If so the freon might be OK and there some sort of electrical problem. In that case it could be low pressure switch, relay ECM/PCM or control panel.
If the pipes did not get cold then it might need freon but it has to get pretty low for the switch not to kick in. As set of gauges would definitely be helpful.
With out more information its hard to know where to go.
Thread Starter
5th Gear
Joined: May 2009
Posts: 5
Likes: 0
here's the deal, I found that the two brown wires from the fuse box to the clutch relay were not getting hot but they were hot at the back of the fuse block so I disconnected them at the relay and ran two new wires from the back of the fuse block to the relay. Now I have hot to the relay but theres only two ways of getting the clutch to kick in(either I ground the low pressure switch or I ground the green wire with white stripe at the relay) this wire is the same wire by the way. If I put a jumper wire across the low pressure switch the clutch will not kick in it has to be grounded???
Instructor
Joined: Apr 2009
Posts: 144
Likes: 0
From: Sacramento CA
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
check to see that the heater valve isn't stuck open. on my 86, it will overpower yor A/C on a hot day. it is vacuum that holds it closed when the A/C is on.
