Gauges

[raf40@oes.amdahl.com (Richard Funnell)]

Q listers,

This was a busy weekend.  I have been putting up with gauges which were
getting loose, and whose readings would change when I turned the headlights
on.  I had planned to add some voltage regulation, but was advised by a
local vendor that bad grounds usually caused such problems.  He was right.

It may have been overkill, but I ended up doing the following:

-       wired in a 2 pin connector to handle the gauge lights, connected to
the original gauges as originally installed.  The light ground is now
separate from the gauge wiring.

-       wired in a 5 pin connector to handle the gauges' sensors, 12v and
ground.  I can now remove the gauge panel by unplugging these 2 connectors.

-       ran gauge 12v from the fuse panel on its own inline fuse.

-       ran the gauge ground to the engine, connecting it to the same point
on the valve cover as the infamous star ground from near the coil.  The
original installed had picked up power and ground from the original
instrument panel.  Don't do this if you want to trust your gauge readings.

-       glued the gauge bodies.  The bodies were splitting as a result of
being over tightened at some point.  I used Locktite Plastix, which I just
found today.  It seemed to work fine.  They are back in the car, tight and
displaying very stable readings, regardless of what I turn on.

For those planning on installing gauges, my original abt panel wiring ran
through existing grommets under the sheet plastic panel behind the firewall
in the egine compartment.  I ran my gauge ground wire through the same
point.

The good news is that everything seems to be great now.  The bad news is
that I had hoped to have a reason to switch to a newer style of gauge.  If
anyone local to the Bay area wants to make an offer on my existing 3 gauges
(oil temp & press., water temp.), I am open.

If anyone wants more info on the wiring requirements, etc., email me directly.

Richard Funnell,
San Jose, California
'83 urQ
'87 560 SL