I just went back and tested the speed sensor (L4) again. It passed! I was measuring in V DC instead of V AC. It gave me .3 V AC. For those of you that have the manual, this is procedure 83-605 step 4. All the steps passed the tests. I think I need a new klima relay... However, I am still not sure if jumping the low pressure switch should engage the compressor. Anybody knows for sure?.
Once again, the only way to engage the compressor at this time is by jumping terminal 5 and 7 in the 12-pole coupling (klima relay removed). I still need to check the high pressure of the air conditioner.