AC quit - ZR-1 Net Registry Forums

Subfixer · 05-22-2021

AC worked great all last year.
This year, nothing.
I have no error codes on the HVAC head unit. All fuses OK.
Watched the Tech 1 display and I have no AC request unless I ground ckt 762, then the compressor runs.
With the system not running, I have about 15 psi at the low side fitting.
When the compressor runs, I have 0 psi at the low side.

Pretty sure most of the freon is gone. Looks like there is a leak inside the pressure sensor where the harness plugs in (looks like some green dye in there). On the hunt for one of those (system is a complete '95 134a system in my '92).

I don't want to have the system refilled only to find out another sensor is bad. More troubleshooting tomorrow.

-=Jeff=- · 05-24-2021

the sensors have an oring and are essentially pushing on the valve in the fitting they attach to. do you see green beyond the inside of the fitting?

I suggest checking the high side gauge port. I ended up installing the correct R12 fitting then I used an aluminum cap (like found on the fuel rail gauge fitting) and I have not had an issue with leaking since

However, I also pulled vacuum on my system and left the gauges connected for a couple days to monitor for any leaks.

05-22-2021	#1
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 384	AC quit AC worked great all last year. This year, nothing. I have no error codes on the HVAC head unit. All fuses OK. Watched the Tech 1 display and I have no AC request unless I ground ckt 762, then the compressor runs. With the system not running, I have about 15 psi at the low side fitting. When the compressor runs, I have 0 psi at the low side. Pretty sure most of the freon is gone. Looks like there is a leak inside the pressure sensor where the harness plugs in (looks like some green dye in there). On the hunt for one of those (system is a complete '95 134a system in my '92). I don't want to have the system refilled only to find out another sensor is bad. More troubleshooting tomorrow. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

05-24-2021	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: AC quit the sensors have an oring and are essentially pushing on the valve in the fitting they attach to. do you see green beyond the inside of the fitting? I suggest checking the high side gauge port. I ended up installing the correct R12 fitting then I used an aluminum cap (like found on the fuel rail gauge fitting) and I have not had an issue with leaking since However, I also pulled vacuum on my system and left the gauges connected for a couple days to monitor for any leaks. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978