I was running through the Bentley section on ECU pin and AMM tests just so I had my bases covered while running down my shaky idle and I came across two things that puzzled me.

First is the pin test for ground on, if I remember correctly, pins 11 and 19, there was no ground to be had. Whichever it was, I traced it back to a two pin black plug near the ECU harness. I thought I remembered there being a jumper in there, checked my 88 and sure enough, there was. So I made one, put it in and all checked well. What is the purpose of this jumper? Is it just a jumper or are there different resistance ratings in there for something or such? Isn't there a timing plug on some euro car or another for different markets?

My next confusion, is the last test in the LH2.2 section of the Bentley, it asks for there to be no continuity to ground with the ac switch off.
I have (you guessed it), 12 ohms or so to ground with the ac switch in any position. This becomes more interesting, when I noticed I can turn the fan switch to anything BUT off, and the continuity goes away. This is still not right, as the other side of the test is that with the ac switch turned on the resistance value should vary, and it does not. I checked the switch itself and both the micro-switch and the varying resistance switch portion work correctly.

Soo.. I'm stumped. I see the ac control switch goes through the heater blower switch, but honestly I'm having a hell of a time making since of the wiring diagrams in the Bentley. Also note the AC does not work, compressor is MIA right now, but I will fix it later. I was on this track wondering if LH was being told the AC was on for some reason, as I'm not clear how this AC system is supposed to work yet. Thoughts?