Mike is certainly right about V8s not having speed semsors in 126 body cars.
The way to the answer is to decide which controller is dropping out. If the temp sensor is the problem then the push button controller is going to be the one that shuts down. The PBC (pushbutton controller) is the one that decides "when", the compressor controller decides "if". The signal from the PBC is a ground signal that drops the voltage coming from the compressor controller and goes through the low pressure switch. This is the easy window. First verify that the proper signal is a ground by watching the signal at the circuit through the low pressure switch (some models use a power signal - only diesel 201 bodies i think but I always verify). Turn the A/C off and on and verify that the voltage is high with the A/C off and low when the compressor is on. Next get the condition to exist and see what is happening at the low pressure switch. If the circuit is still grounded then the PBC is doing its job, the temp sensor can't be the problem and the problem exists in the compressor controller under the hood.
Bosch Master, ASE Master, L1
33 years MB technician