AIR CONDITIONING 1B-19 Reading Sight Glass The sight glass provides accurate diagnosis only under the following conditions. If the vehicle can be tested under these conditions, check the sight glass appearance and compare to the chart. Engine speed 1,500 RPM A/C switch “ON” Blower fan operating at highest speed Air source selector lever at “RECIRC” Temperature control knob at coldest position Ambient temperature below 35 ° C (95 ° F) and hu- midity below 70% Notice: If the vehicle cannot be moved to a testing location that meets these specifications, then the sight glass cannot be used for diagnosis.
You must discharge and recover the refrigerant, then recharge the system with the spec- ified amount of refrigerant. Then continue checking the system performance. High side pressure less than 1667 kPa (17 kg cm 2 / 242 PSI) Notice: If the high side pressure is greater than stated, the sight glass cannot be used for diagnosis. You must discharge and recover the refrigerant, then recharge the system with the specified amount of refrigerant. Then continue checking system performance. High and low pres- sure pipe temper- ature The high pressure pipe is hot and the low pres- sure pipe is cold. There is a distinct difference in temperature between them.
The high pressure pipe is warm and the low pressure pipe is cool. There is no great differ- ence in temperature between them. There is little difference in temperature between the high pressure pipe and the low pressure pipe. The high pressure pipe is hot and the low pres- sure pipe is slightly warm. There is a differ- ence in temperature between them. Sight glass condi- tion Almost transparent. A flow of bubbles can be seen, but they disap- pear when the throttle is opened. A flow of bubbles always can be seen. It appears sometimes transparent, and some- times frothy. Something like fog faintly can be seen.
Even at idle with the fan at “HI” (with the window fully open), the bubbles cannot be seen. N1A0072E N1A0073E N1A0074E N1A0075E Air con- ditioner cycle condi- tion OK NG (Not enough refrigerant) NG (Almost no refrigerant) NG (Too much refrigerant)