Hi Josh,
Update info on the temp gauge trouble. I had the
wiring correct, sender to "S" and power to "I"
(ignition?). I swapped the wires on those
terminals and my mate observed the needle deflect
to zero from high, as the engine was hot.
I'm guessing it is not a Wheatstone Bridge
arrangement (or being on "the Left Coast" we'd
prefer a Whole Wheatstone Bridge arrangement).
Anyhow, digging around with a multi I couldn't
believe finding only 7 volts at the gauge. The +
and ground wire on the harness to the panel are
large, say 12 ga.for glow plug load. The ground
pigtails to gauges are 14 ga but the first joint is faulty.
I had a little jumper, say 18 ga, and went from
temperature gauge to harness ground and
everything came up to house voltage and indicated
temperature dropped to 175 F and the tachometer
came to life with a proper ground path too.
The weather forecast is looking okay for that
little cruise & lunch at the Dinghy Dock Pub with our guests from Denmark.
Cheers, Russ
Sweet 35 mk-1
At 09:02 PM 13/03/2017, you wrote:
Hi Josh,
Thanks for the tip. I hope it's as simple as a
dufus move with sensor and IGN connections.
Fortunately I made a colour coded wiring diagram
when I changed from the Catalina panel to Sweet's panel.
I'll track that down this weekend, along with
the tach wiring. It's a sensor lead type unit
fed from alternator stator that worked for the
garage setup, temporary measures of course, but
decided not to work in a real life situation.
The rest of the engine install has been
successful. Oh joy. I can get to the Dinghy Dock
Pub this weekend, with guests from out of town.
Cheers, Russ
Sweet 35 mk-1
At 05:16 AM 13/03/2017, you wrote:
You can put a simple variable resistor in
series with the temperature probe. Or you
could put a simple voltage regulator circuit on
the 12v supply. You could church it up by
making the voltage regulator adjustable.
There might be something wrong with the gage or
a ground path since most temperature sensing
systems are designed to work independent of the
input voltage. A wheatsone bridge is normally used.Â
<https://en.m.wikipedia.org/wiki/Wheatstone_bridge>https://en.m.wikipedia.org/wiki/Wheatstone_bridge
A simple mistake in the wiring could be the
cause too. Typically the gages have a 12v
supply, ground, and sense (or D from the
picture in the link). If the 12v and D wires
attached to the gage were swapped I think you
would see the resulting indication which you
are having. I'd take some voltage readings at
the temperature probe and at the gage. While
you're there check the resistances of the
ground wire and the sensing
wire. Particularly important in this case is
the meter usage good practice of checking for
no voltage before checking resistance.
Josh Muckley
S/V Sea Hawk
1989 C&C 37+
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