The question is, how much do you really want to know?

Vacuum is pretty useless unless you have a turbo and can watch the boost
kick in.  It will only show big vacuum leaks, way out of spec timing, or
bad valves; all of which you can avoid with good maintenance.  Oil temp
is useless too, I had one on my old 1600 years ago and it just scared
the hell out of me.  But I ran all day in 100 degree temps with the oil
at 260-280 with no problems.  Many modern cars will run with oil at 280
degrees, especially when towing, and oil is designed to handle that.
The ammeter is useful, but the voltmeter is much easier to install and
tells you essentially the same thing.  If charging drops, so will the
voltage. Cooling system pressure is really a bit of overkill, if you
loose a pint of coolant due to a leak your light will start flashing and
warn you of the problem.  You will see it long before you notice the
gauge is reading low.

I recently added a voltmeter and oil pressure guage, and used the dual
VDO sender that retains the warning light.  I highly recommend you
retain the warning light since you need something to grab your attention
fast when the oil pressure drops to zero.  This happened to me on the
way to work, a line cracked on the external oil cooler and dribbled out
oil for about two miles before the light came on.  Who knows how much
farther I would have gone attending to driving in rush hour traffic
before I noticed the gauge was at zero or the smoke started pouring out!

Have fun, and remember the Vanagon is not an airplane cockpit, so don't
get too carried away!

Stuart MacMillan
Manager, Case Program
800-909-8244 ext. 8208
Fax: 206-269-6360

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