AC compressor shut offwhile driving???

[HAFROD]

I was headed to parts store and about 3 miles into my journey, the blower motor shut off. I came back home and checked the big 4 pole plug in by the rear RH valve cover. The plug was melted. I cut off the melted end of the plug and crimped on some insulated female spades and plugged them in. I test drove it again and about a mile into drive the AC compressor shut off and the vents were blowing warm air. So the blower motor is working on high but compressor clutch not engaging. I never hear the AC clutch cycling, it just always stays engaged when AC is turned on at the control panel. I checked all AC parts plug ins and nothing is jumped or messed with other than the 134 changeover previous owner done. Could this thing be low on Freon? It's been about 10 years since I changed one to 134 and charged in the driveway. I charge it on the small aluminum line right? I know it probably needs the leak found and O rings swapped with a new drier and orifice tube but don't want to get into that right now. I seen a commercial for AC Pro and it is at my local WalMart. Don't know if it has the correct end to plug into my line. The adapter for 134 is on that small line port on my ElCamino

 

[HAFROD]

So I've been messing with it for about an hour in the driveway. With the AC Pro gauge, its reading in the blue and barely on the yellow which says ALERT but it moves up and down a little. The compressor clutch is NOT cycling. It stays engaged. That gauge should read same pressure if it's not cycling right? reading on the gauge is around 37-45psi. Why would my compressor not cycle?

 

[Texas82GP]

I wouldn't expect it to cycle if the low side is between 37-45. Turn the fan speed down to low and roll the windows up. The low side should fall until the clutch cycles. Post back if it doesn't. Here is a temperature/pressure chart with the temperature being that of the air going across the condenser. You should take your pressure readings with the windows down and the fan speed on high when using this chart. Consider buying an inexpensive manifold gauge set from Harbor Freight. Hope this helps.

 

[Texas82GP]

^^R134A chart. Wanted to be clear.

 

[Ribbedroof]

The small line is the high pressure side. You do not want to charge into the high side with over the counter stuff, there should be a low side fitting on the accumulator

 

[tkruger]

Mine was converted but needed several cans to get it to work. I do not remember the number but after the second can I was thinking this is not going to work. Into the third it started to cycle. Did you buy the 134a with compressor oil in it?

 

[HAFROD]

When the Matco truck showed up today at my work, I bought a gauge set and a digital thermometer. I'll check it out this weekend. I used the AC today on the way home and it was fine