# A/c recharging **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [May 21, 2008, 8:13pm UTC](https://community.cartalk.com/t/a-c-recharging/14302 "2008-05-21T20:13:41Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Jeffmw05](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@Jeffmw05](https://community.cartalk.com/u/Jeffmw05)\ **Post date:** [May 21, 2008, 8:13pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/1 "2008-05-21T20:13:41Z")
I hooked up the pressure gauge to my car today to check psi in the system prior to recharging and got 0 PSI (refrigerant disconnected), which seems impossible because the compressor was engaged and the a/c was cooling to around 60 degrees. Does my can of refrigerant need to be at the other end of the hose for pressure to register ? I don’t want to risk recharging w/ a bad gauge in order to not overcharge the system. Advice ? Thanks. jeff ---
**Author:** ![Jeffmw05](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@Jeffmw05](https://community.cartalk.com/u/Jeffmw05)\ **Post date:** [May 21, 2008, 8:34pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/2 "2008-05-21T20:34:00Z")
Update: I tried checking the pressure with the can connected at the other end (was careful to not puncture the can) and still got 0 PSI. Do I have a bad gauge or is 0 PSI correct and I should just go ahead and charge until the pressure is within the proper cooling range ? ---
**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\ **Post date:** [May 21, 2008, 9:23pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/3 "2008-05-21T21:23:58Z")
Zero is not correct. ---
**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\ **Post date:** [May 21, 2008, 11:42pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/4 "2008-05-21T23:42:26Z")
I concur. Bad gauge. ---
**Author:** ![wizard](https://avatars.discourse-cdn.com/v4/letter/w/a87d85/32.png) [@wizard](https://community.cartalk.com/u/wizard)\ **Post date:** [May 22, 2008, 12:20am UTC](https://community.cartalk.com/t/a-c-recharging/14302/5 "2008-05-22T00:20:30Z")
Question, Are you sure you are not connected to the vacuum side? ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [May 22, 2008, 12:20am UTC](https://community.cartalk.com/t/a-c-recharging/14302/6 "2008-05-22T00:20:50Z")
It’s also likely that the pin in the gauge connector is not depressing the valve in the car’s service fitting for some reason. ---
**Author:** ![crankwalk5](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@crankwalk5](https://community.cartalk.com/u/crankwalk5)\ **Post date:** [May 22, 2008, 12:31am UTC](https://community.cartalk.com/t/a-c-recharging/14302/7 "2008-05-22T00:31:23Z")
what are we working with? (FGS),year ,make ect.)R12,134-A. full gauge set (wal mart stuff)need more info? and when in doubt charge by temperature. you say 60 degrees ,I respond what was the ambient temp? dual A/C? single unit? ---
**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\ **Post date:** [May 22, 2008, 12:41am UTC](https://community.cartalk.com/t/a-c-recharging/14302/8 "2008-05-22T00:41:24Z")
The suction side is the charging side. The pressure should still be 25-45 psi. Any lower, and the low pressure sensor will turn off the compressor. The one in my car trips at 18 psi. The high side uses a much larger port, and can get to 250-375 psi. You cannot fit a charging port to the high side by accident with an R-134A system. ---
**Author:** ![Jeffmw05](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@Jeffmw05](https://community.cartalk.com/u/Jeffmw05)\ **Post date:** [May 22, 2008, 2:25am UTC](https://community.cartalk.com/t/a-c-recharging/14302/9 "2008-05-22T02:25:58Z")
87 Accord, 134a, partial gauge set (low side only) Ambient temp was approx 70 degrees. Single A/c Should I throw out that gauge and try another ? ---
**Author:** ![crankwalk5](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@crankwalk5](https://community.cartalk.com/u/crankwalk5)\ **Post date:** [May 22, 2008, 2:28am UTC](https://community.cartalk.com/t/a-c-recharging/14302/10 "2008-05-22T02:28:39Z")
so i assume it has been converted to 134-A ? ---
**Author:** ![Jeffmw05](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@Jeffmw05](https://community.cartalk.com/u/Jeffmw05)\ **Post date:** [May 22, 2008, 5:13am UTC](https://community.cartalk.com/t/a-c-recharging/14302/11 "2008-05-22T05:13:36Z")
Yes ---
**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\ **Post date:** [May 22, 2008, 8:11pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/12 "2008-05-22T20:11:07Z")
Hopefully, no one bypassed the low pressure cutoff switch. Make sure the new service port is full screwed down onto the old valve. I suspect ok4450 is correct that the valve pin isn’t being fully depressed. ---
**Author:** ![rrhoff](https://avatars.discourse-cdn.com/v4/letter/r/8e7dd6/32.png) [@rrhoff](https://community.cartalk.com/u/rrhoff)\ **Post date:** [May 23, 2008, 2:14pm UTC](https://community.cartalk.com/t/a-c-recharging/14302/13 "2008-05-23T14:14:09Z")
is that the same gauge that came with the can of 134a? because their not accurate at all.they sell better gauges seperate from the can.that is what i had to do.