This problem that i have has been discused before, but mine is different as it seems to be temperture related.

The problem is that the compessor cycles properly if the ambient temperture is below 25c. If above 25c the compressor will lock lock out after cycling for the first time, the only way to get it going again is to turn the ignition off then back on again. It will also stay on permently if the fan speed is at full speed, and is nice and cold.
I know that it`s been said to look at the belt tension and the speed sensor, these seem to be working correctly, and how could these be affected by the ambient temp. The system works perfectly if the air temp stays below 25c.

Thanks to anyone who has the answer for me to fix this problem.