Keith,

I had this problem in my 85 after I put in an instrument panel with a
tach from an 87.  The high pressure sender was added in 86 and later
models.  So, mine had no signal since there was no sender.  Mark
Drillock, IIRC, explained to me how to ground this and fix the problem
in the 85.   I also found some info from searching the archives that
explained how the system could go wrong and be fixed for the post 85
models.   I have attached what I saved on my hard drive in a zip file.

The gist of these posts is that you are on the right track in suspecting
that there is a continuity or connection problem somewhere.  These will
give you a good understanding of the system and ideas as to where to look

Check for grounds and connections again as you have said you planned to do.

--
Sam Walters
Baltimore, MD

89 Syncro GL, Zetec Inside
85 Westy Weekender
85 Mercedes Benz 300D Turbodiesel - to become veggie oil powered

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