Get yourself a 12V test light if you don't have one. (Should be around $7). When the A/C has cut out, disconnect the power wire going to the compressor. Clip the alligator clip on the test light to ground, and stick the probe into the compressor power connector on the source side. (Engine running, A/C switched on.) If the test light comes on, then the superheat switch is probably shutting down the compressor. If not, something else is keeping the A/C relay from engaging.

If you are sure that your system has sufficient charge of refrigerant, verify that the electric fan is coming on with the A/C and that the condensor is clean and free of debris.

I'm not sure if your symptoms point to superheat switch or not. On my car, the A/C cuts out when outside temperature is over approx 95 degrees F. Below that, it will work fine indefinitely. Cutting in and out every 10 minutes sounds more like low refrigerant charge or a blocked orifice tube. There are two pressure switches - the Pressostat, which is a 2 wire connection on the low pressure line, and checks for low pressure, and a pressure switch, which on 70 series is a 3 wire connector and checks for high pressure. (I'm not sure what else it does. The 3 wires suggests that it has two functions.) On the 850 series, it may be a 4 wire connector. If pressure gets too high, it is supposed to tell the ECU to cut off the compressor and turn the fan to high speed. In this case, the test light would not light when you check at the compressor power connector mentioned previously. On the 70 series, the pressure switch is located on the high side refrigerant line, not too far from where the service port is located on the low side line.

On the 850 (different on the 70 series), the circuit is as follows:
The signal from the climate control panel goes to pin 86 of the A/C relay. The ECU provides ground on pin 85. 12V power is always present on pin 30. When these conditions are met, the relay closes and provides 12V out on pin 87 of the relay.

This signal goes to pins 2 & 4 of the A/C pressure switch via the BL-GR wires. The signal goes, via the GN wire, to the ECU and the Pressostat and on to the compressor clutch (through the superheat switch, if so equipped). At the same time, if the presure gets too high, the pressure switch will supply a signal to the ECU on the BR-GR wire. The ECU will remove ground from the A/C relay, disconnecting the compressor.

On the 70 series, the A/C relay is located in one of the underhood fuse boxes. There is a label under the box cover telling you which on is which.