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

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.

On 4/22/2008 9:13 PM jim beam spake these words of knowledge:

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.

In your narrow world.

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

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.

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

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.

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.

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.

And they are not the audience the carmakers want.

Not harmless at all--it costs the money.

And 99.99% of the people won't learn and will never care.

You need to get out more.

nah - there's a HUGE difference between those that /think/ they know and those that /actually/ do. i know that from having been on both sides of the vehicle fence - pure engineering and technician. even if you gave an "enthusiast" a "real" temp gauge, what are you going to do with the information? i know a thing or two about vehicle design, but unless i had a specific usage/conditions map for my vehicle, i wouldn't be able to "use" the readout. and even if i did, it /still/ wouldn't mean anything substantive to operation unless it was over spec!