1985 300D Klima

[ROLLGUY]

I have been reading up on Klima issues in these threads: http://www.peachparts.com/shopforum/diesel-discussion/386849-compressor-speed-sensor.html
http://www.peachparts.com/shopforum/diesel-discussion/394965-87-190d-2-5-ac-questions.html
They deal with the speed sensor issues and the Denso compressors. There has been many times that I have done a Sanden retrofit on an '85, and can't get the compressor to engage. I have always just jumped the terminals to get the compressor going, in order to charge the system. Only on one car (my bro's) did I actually look for the fault. I found it had corroded terminals on the EGR computer socket and plug. A little wire brushing on the plug, and a good used EGR computer fixed the tach, and the compressor clutch problem. Since the 85's don't have the compressor speed sensor, the main cause of a non working clutch is the lack of tach signal. For Mxfrank, Diseasel300, and others- is there an easy way to modify the Klima so the compressor clutch will work as it should when called for by the PBU? I imagine the same circuit and components as used for the later models would work. However, I am not good at electronics, and most of the terms used in the above threads went right over my head. I am just looking for a way to make the '85 system work like the earlier models (no Klima). Most of the time the customer wants the A/C to work, and doesn't care if the tach works or not. They also don't want to have to remove a jumper if they want heat. I have no more good EGR computers left, so even if that is what is wrong with the next one I do, I won't be able to get the A/C going short of using the jumper. Thanks in advance!