Yaris, Scion xD, Honda Fit - no water temp gauge

How is such an aftermarket temp gauge installed - under the hood, and
how is it mounted on the dashboard/instrument panel? How much does
it
cost?

 

You need to locate the temperature sending unit on the block and find
a place in the interior to mount a gauge.

When you buy a gauge you should get a sending unit with two
connections - one for the idiot light and one for the gauge. Hook
them both up, wire the gauge and you are off and running. The hardest
part will be finding a keyed power source for the gauge and a proper
ground. It's really pretty straightforward if you have worked on cars
before. If not, just have a local mechanic do the work.

 

just use the engine computer to give temperature output. its sensor is
best located to get the best reading, unlike a bolt-on.

 

Or, just buy the gauge that plugs into the standard OBD II port and
displays lots of things.

 

He was clearly talking about the use of actual working gauges,
specifically as opposed to those which are dressed-up idiot lights.

RFT!!!
Dave Kelsen

 

Because /not/ wanting one is just stupid. Sure, there are reasons for
el-cheapo line cars not to have a gauge, and that's fine. But for any
driver to say "I'd rather have a light" is just flat dumb. No way around
that.

What really gets me is the idiot gauge- costs MORE than a light, but is
less useful (because it doesn't attract attention, and worse yet may
even give the unwitting driver the impression that its a real gauge.

Not at all. Gauges do warn you before things get critical, and you
blatantly left out the obvious part of the second statement, which is
that a gauge will tell you when some things are wrong WHICH A LIGHT
WON'T TELL YOU. Hence my examples of 1) a dead electric fan which was
indicated as a slightly abnormal gauge reading but which was not far
enough out of range to have turned on a light, and 2) abnormal oil
pressure behavior which indicated a collapsed filter causing the bypass
valve to open, but was technically within the "normal" range and never
turned on the idiot light.

No, I never said that YOU read it that way, but its not what I said. I
said that "idiot" gauges (the kind that are just controlled by a switch
which either sets them to the normal range, or drops them to zero) are
just idiot lights with pointers. I never said that real analog gauges,
whether mechanical or electric, are idiot lights with pointers.

No, you're just showing the fact that you aren't actually reading (or
comprehending) posts, you're reading a few words then shooting off your
message while missing the main points. As has been the case every time
you blunder into rec.autos.tech.

 

And even though its mostly window dressing, it does come in handy even
in an automatic car to indicate if the transmission starts slipping, TC
clutch fails to lock, etc. But yeah, 99.999% of the life of the car, a
tach in an automatic is worthless and a prime example of something
that's there ONLY for marketing.

Agreed. Sad though the result may often be....

 

Of course, you CAN call up programs that do monitor and put a "gauge" on
all of those items. Right now I have a CPU utilization bar graph in the
lower corner of my screen. I can switch it to network I/O, disk I/O, or
disk space used if I want.

Good engineering really means making the RIGHT information available at
the RIGHT time. With a car, the critical things that need to be
displayed are fairly simple: Engine temperature, oil pressure, speed,
and fuel remaining are the big 4. The best designs, as I have said, make
all 4 available as analog readouts, and ALSO will turn on an
attention-getting light and/or ring a chime if any of them (except
speed) get out of the normal range. That's been done for decades (my
wife's 1993 car being so equipped) so its just DUMB to regress.

The point I've been belaboring is that to reduce oil pressure and water
temperature to ONLY a warning light is actually denying the driver
information that he/she might occasionally want or need, and which can
be valuable. Certainly the average driver doesn't need to know the
exhaust gas temperature and oxygen content, but with only 4 basic
readouts really NEEDED, why deny any one of them? It would be a
different matter if there were 10 parameters equal in importance to oil
pressure and coolant temp and designers would have to start making
decisions about what needs to be primary and what could be secondary,
but there just AREN'T!!

 

There are a couple of different types. An old-style purely mechanical
gauge has a pressure bulb that gets screwed into a coolant passage in
the engine block (you can often "tee" a fitting in so that it shares the
same coolant port as the car's own idiot light sensor. A capillary tube
runs to the gauge mounted on or under the dash. These are usually very
accurate, even for the cheap models under $25. The drawback is that you
have to be very careful in routing the capillary tube because if it
becomes kinked or broken, the gauge is useless. You also have to have a
large enough hole in the firewall to feed the pressure bulb and
capillary through.

Electric gauges have an electric sensor that goes in the coolant, just
like the capillary bulb. But you can install it, and then route the
power and sense wires however you need to. They're more expensive, and
the lower end ones are not always very accurate.

 

Because /not/ wanting one is just stupid.[/QUOTE]

In your narrow world.

In the real world, plainly, things are way different.

 

Not at all. Gauges do warn you before things get critical,[/QUOTE]

You are assuming one HELL of a lot here. You assume that people know
how the machinery works in the first place. That's a strong presumption.

Without the operator knowing how the machine works in the first place, a
gauge is absolutely useless.

See, your mind is in a very, very narrow place. YOU wanted to know how
the thing works, so YOU found out. Others don't know, don't want to
know, and in many cases can't understand it even if they try. A gauge
is useless to those people.

The world where all you need to know is that "gauges warn you before
things get critical" is Springfield, and Homer Simpson runs the nuclear
power plant equipment.

 

Steve wrote:

and i never said. "wow, what a fucking idiot!!!"

 

what's the point when the engine computer can output the data for you????

 

You are assuming one HELL of a lot here. You assume that people know
how the machinery works in the first place. That's a strong presumption.[/QUOTE]

No, not really. I remember in driver's ed, a few decades ago, the
instructor explaining to us that every few minutes you should move
your eyes over the instrument panel and look at the gauges and see that
they are all more or less nominal. If anything is in the red, pull over
and call for help. If you notice it moving toward the red, get ready to
pull over and call for help.

No, they still have eyes. Now, it's true that there are people who do
not do the periodic glance over the instrument panel and notice where
everything is, every few minutes. That is bad, but it's an easy skill
to learn.
--scott

 

The point is to have a nice clean interface that you can look at every
few minutes when you scan the panel.

The engine computer can give you all kinds of useful information, but if
you have to page through a dozen menus to get it, you will never see it in
time. And information you never see is not useful.
--scott

 

I remember them teaching us to always use turn signals...

You can lead a horse to water, (you can even shove it's head down in the
water,) but you can't make it drink.

 

No, not really. I remember in driver's ed, a few decades ago, the
instructor explaining to us that every few minutes you should move
your eyes over the instrument panel and look at the gauges and see that
they are all more or less nominal. If anything is in the red, pull over
and call for help. If you notice it moving toward the red, get ready to
pull over and call for help.[/QUOTE]

If all you're looking for is "in the red, pull over" then a dash light
does a MUCH better job of alerting you. That's simple psychology.

Unless you know the principles of operation of the whole machine, the
gauge will indicate nothing to you. It may be behaving perfectly normal
within its own context, but if you don't know the context then you don't
understand its behavior. If the needle wiggles around up and down, the
guy who has no idea what the gauge is for will worry. Hence the "idiot
light driven gauges".

And if all you end up with are "idiot light driven gauges," then just
put in idiot lights. You save money, and you get a better alert.

 

1) cost
2) simplicity
3) redundancy

 

You are assuming one HELL of a lot here. You assume that people know
how the machinery works in the first place. That's a strong presumption.[/QUOTE]

A minority, but fairly large, percentage of car buyers are enthusiasts
that understand how things work.

My wife doesn't have a clue how things work. She still told me, "the
temperature gauge on my car is going about a half-division higher than
it used to when I'm at a light, do you think something might be wrong?"
That's when I found the dead fan motor. That would have never...
NEVER... happened with a light or an "idiot" gauge that snaps to its
normal range or to 'overheat'. The gauge in her car is entirely modern-
its digitally driven by the body control module based on a feed from the
powertrain control module, which gets the information from the analog
sensor... HOWEVER, it moves linearly and accurately with temperature
inside the normal operating range and a bit to either side, so you can
very clearly see small changes. Its the best of both worlds.

Not as narrow as yours, apparently. You're the one that wants to force
every driver to the lowest common denominator of instrumentation.

Its also harmless to them. Better yet, after watching a gauge a while,
they'll learn what it means just like my wife did.

 

Not true at all for something as simple as oil pressure and water
temperature! This isn't rocket science.

And my grandparents and great-grandparents, some of whom never completed
high school (and at least one grandmother CERTAINLY didn't "understand
the operation of the whole machine") read analog temperature and oil
pressure gauges perfectly well. Never melted down an engine, never took
it in to the mechanic unnecessarily either. Are you telling me that
driving-age people of 2008 are simply too stupid to do such a simple task?