Dec 31, 2014 (5 years ago)
I'm not 100% sure on this one,
and the manual is at work,
not where I am right now,
So going on memory these are old style and both gauges are fed by a voltage stabaliser,
idea being so as to "smooth" out voltage fluctuations and give a steady gauge read,
and when both gauges go then it's a good bet the stabeliser is shot.
At the moment best guess is it's at the back of the gauge cluster so that has to come out to get at it.
If I'm right that is?
I'll be back at workshop on Friday so I'll check the manual then and repost if nedded.