Automotive Air Conditioning Information Forum

Hello everyone, this is my first post, so please be kind!

I have a 1991 Volvo 240 that has been retrofitted from R11 to R134a. While the ac is somewhat cold, I am a little confused with the meaning of the manifold gauge readings. [url=https://postimg.org/image/pujgpd0l ... .jpg[/img]image sharing[/url]

Granted, this is an el-cheapo model of a manifold gauge set, but I don't think the high side should be this low

[url=https://postimg.org/image/pt9ivxyr ... .jpg[/img]pc screenshot[/url]

Outside air temp:
[url=https://postimg.org/image/3st6fbg3 ... .jpg[/img]photo uploading[/url]

Air through vent on MAX and recirculate mode enabled:

[url=https://postimg.org/image/pqpn93v4 ... .jpg[/img]photo uploading[/url]

Any ideas on where to start?

Thank you in advance for your tips and suggestions!

High side lone is hooked to an R12 Low side service port.

Follow the lines from the condenser back for the High side port. Normally the bottom line from the Condenser.

Tim wrote:High side lone is hooked to an R12 Low side service port.

Follow the lines from the condenser back for the High side port. Normally the bottom line from the Condenser.

Thanks, Tim. It is just strange that there was a fitting on the high side that fits the cold side gauge, and no fitting for R134a on the cold side.

durk80 wrote:
Thanks, Tim. It is just strange that there was a fitting on the high side that fits the cold side gauge, and no fitting for R134a on the cold side.

Sorry but this makes little to no sense. You attaching both gauge lines to the Low/Suction side of the system. You have an R12 system someone is trying to convert to R134a. They placed (1) low R134a Adapter on the line were you have your Low side (Blue) guage attached.

The (Red) hose is attached to the (Low) Side R12 Service port, that they left alone when converting.

Tim wrote:

durk80 wrote:
Thanks, Tim. It is just strange that there was a fitting on the high side that fits the cold side gauge, and no fitting for R134a on the cold side.

Sorry but this makes little to no sense. You attaching both gauge lines to the Low/Suction side of the system. You have an R12 system someone is trying to convert to R134a. They placed (1) low R134a Adapter on the line were you have your Low side (Blue) guage attached.

The (Red) hose is attached to the (Low) Side R12 Service port, that they left alone when converting.

You are right again, Tim. I presumed that the receiver/dryer was where I was supposed to hook up the gauges.
Can you tell how much of a noob I am?
After figuring this out, I did some googling, and the high side fitting is located under a hexagonal cap on the compressor body.

Tomorrow, I'll have to take some 'real' readings. Thank you for pointing this out again, Tim, and for going easy on me!

Hi Durk, I recognize your name from the turbobricks forums.

Little something I've noticed with the volvos, we don't have a high side pressure port! We simply have a low pressure port, usually located on/near the receiver drier. I believe that many of the cars had the port on the back of the compressor, but some retrofits (as well as most later model cars) had the low side pressure port on the R/D, or on the low pressure line leading to it.

Also, your images are not working for me.

Edit: apparently we sometimes have a high pressure port on the back of the compressor too, but I have never used it and I've seen compressors without it I think.