That connector that is taped to the harness is the test port for the DIS system. That is the back probe point and the place where the adapter from a TECH 1A plugs into to run ignition simulations & read system performance and check for grounded & or open circuits. Of course that software is optional & hard to find.
I would like to thank you very much for taking the time to post up the heater core r&r.
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I keep dreaming that I will never have to do this job.....