compressor - tach connection

[jmann.arch]

I have been gradually fixing an A/C/blower issue on a car that sat for a few months. Yesterday I fixed the blower motor by replacing the regulator. I thought I might need to add some refrigerant/oil to get the compressor to kick on because it didn't. I picked up some R134 w the oil and went to charge the system - but the valve that came with the can said the pressure was fine - so it appears I really don't have a leak.

I had noticed recently that my tachometer had stopped working (before I got the blower fixed) - and had read on some of the posts about the tach indicating engine speed let the compressor know when to come on.

Is there a test for the overload protection relay?

I took out the compressor control module - mine is labeled D-KLI/KD - I assume this is the Klima? I tried jumping pin socket 5 to 7 on the socket in the hopes that the compressor would come on to no avail.

Is there a way to definately tell that the tach issue is connected to the compressor not starting? I have not found anything in the cd manual that helps out with this one.

Jimmy