When I jump the relay the compressor kicks on so the wiring should be fine between the relay and clutch. But I checked anyway for continuity on the wire between the relay terminal that feeds the compressor clutch and it read 1.4 ohms. Then something has to be amiss in the area of the relay...maybe ...

Bringing an end to this thread... The problem is solved. I didn't understand the VD compressor concept previously, and upon following your recommendations, everything seems to be working upon my most recent recharge. I also did not realize the length of time this process takes. In all, it probably ...

A blinking A/C-switch light on a Toyota product means that a difference in RPM exists between the engine and compressor. The blinking light further indicates that the compressor's drive belt is slipping and that it is momentarily seizing or has completely seized. The question is, why? From your desc...

Okay...we've got the system charged to specs. It could also be the wiring from the relay to the clutch, the diode that prevents stray voltage induced from the clutch coil from traveling back to sensitive electronics, or the PCM itself. Try the easy test first. Put a VOM's test leads across the wire ...

I agree with Tim. In addition, whenever I see a question like yours, my response is to first and foremost, install the correct amount of refrigerant into the system that the manufacturer's specifications call for. The process involves recovering the refrigerant that's in the system now (or having a ...

I'm not surprised that you haven't received any replies to your latest posts. You seem to want to get deeply involved in refrigeration science and system-design, and that's fine. But I would hazard a guess that more than 99-percent of this Forum's members simply don't have the background for such a ...

This is a cobbled together system in an early Mustang. Which model year is this Mustang? I presume you've charged it with R-134a. Do you have the original R-12 specs for this car as a baseline? When first started at idle, the pressures settle to 25/150 on a 70F day and it blows 44ish out the vents....

With the multiple capabilities of your scan tool--probably more advanced than what the parts suppliers have--you might be able to identify the issue that's causing the no-shut-off problem and fix it yourself. Just replacing the switch with an OEM part might also correct it. Last resort is taking it ...

I mixed-up my responses. Apologies for the confusion. Getting back on topic, if the switch has failed "open" and needs to be replaced, it's possible that the system set a hidden trouble code that's causing the problem of not shutting off. Most parts outlets like AutoZone can scan it for yo...

You jumpered the thermal switch, which is prone to fail, and the system came on. Chances are, it's the switch that's defective.