I read your problem and have seen Art's and Paul's post on the subject. I have not had a problem with this yet on my '86. I have not been brave enough to make the changes either.

For a thought. They mention a solid state power regulator that controls the current to the speedometer and gauges. I was thinking it may have been bad to begin with. Now with less components it is able to throw things in a more worse direction?



On my '78 I had the wire that ran from the temp sensor. Go to ground. Down low on the engine from inside the harness. It was a worn spot.

Kept doing it intermittently. Scares the bah--g's out of you the first few times.

In other post I have read. I wondered why some people would have a oil pressure gauge over a good temperature or voltage gauge. I have heard of more problems with battery charge, cooling water problems, than oil problems these days.

You really got to go some, to get today's oil to lump in the pan. High heat or cold, enough to damage or plug a pump. Sludge is virtually eliminated.


Anyhow,
I would contact the more knowledgeable fellows I mentioned.

Regards,

Phil