Wanted to confirm the above as working.
In my case, my AC and such was all functional, just could never get a response from the tach. I finally got around to doing this. Popped my door and popped the plug from the EGR computer, expecting to find nastiness like others have reported. My pins and harness are pristine, like new. I figured I'd disect the computer just to look since I will not be replacing it. Again, like new.
As such, I have no idea why my EGR system and everything else worked fine, but the tach wouldnt.
I grabbed some scrap 22ga speaker wire and shorted pins 20 over to 25 and 16 over to 14. Instant signal. Its reading low... 500rpm idle, 3100rpm no load governed. Not sure if the reading discrepancy lies within the jump "around" the EGR computer, or in the junkyard replacement sensor I swapped in a month ago to try and fix the problem.
Either way, here's some pics for those of you that are diagram challenged.
And my final product once I trimmed down the excess. I tucked it into the opening around the edge. Theres no reason for the wires to come loose from their pins let alone fall out with the middles being jammed into the gap.
I would guess, ideally, you'd put a zip tie or something around the plug to be sure nothing moves. Whatever. I fixed my tach for $0. I slid the EGR computer back into its "port" and laid the plug on top. Once I replaced the kick panel, the plug cant move anywhere.
