AU Falcon, temp gauge seems low

Can anyone advise if this seems normal?
1999 automatic AU Forte stationwagon, 180,000km. We bought this car about 3 months ago and have no previous experience of Falcons.

Under normal driving conditions, the temperature gauge sits just out of the "cold" range:
http://i1010.photobucket.com/albums/af230/RRM22/Mobile%20Uploads/CAM02474_zpsp1sqopwi.jpg And after driving as fast as common sense and the law allows up the Rimutaka Hill, this is the highest I've ever seen my temperature gauge read:
http://i1010.photobucket.com/albums/af230/RRM22/Mobile%20Uploads/CAM02467_zpsqh4ghh48.jpg

Just above the "N" in "Normal."

Is this normal for Falcons? Most cars I've driven the temperature gauge will normally sit at about 40%, and might maybe get up to about 50% if you drive really hard in stop-start traffic in the city in summertime.

The heater on this car works fine, but it doesn't blow quite as hot as I would have expected.

When I open the bonnet after driving there is plenty of heat in the engine room!

Radiator header tank has nice clean green coolant right up to the "Full" mark.

There is plenty of power, the engine does not appear to be running in any sort of 'limp home' mode.

There is no rich mixture smell. If the ECU was getting a low temp signal from a temp sender unit, so that it thought the engine was not up to running temp, I would expect it to be giving a bit of choke all the time, resulting in a rich mixture smell.

Do the temp gauge and ECU have separate coolant temperature senders? Could it be a faulty gauge sender?

Or could this be a faulty thermostat? (Every other car I've owned, a thermostat failure causes overheating, not cold running!)

Most will fail in the open position, sounds like thermostat to me (o:
Maybe radiator is a bit blocked and someone took the thermostat out, seen that done many a times.

It does indeed need a new thermostat, 10 minute job, very common fault. The gauge should sit between O and R under most conditions, towing something on a hot day or doing hill work is the only thing that will push it a bit higher when using a standard radiator. For your own reference AU 6's use a cylinder head temp sensor that will progressively shut the engine down if over temperature. you can't cook it because the PCM won't let you. It is best to get the genuine Ford thermostat too, they work better than the aftermarket ones due to having a more progressive opening which tends to put less thermal stress on the radiator tanks and tubes, it makes them last longer basically.

^^^^^^^^^ Smack on

franc 123 is so clear. thanks franc for your help to so many

No problem, I give back where I can. Being in the trade for so long and having to write up thousands of repair orders on what I've done and why I've done it in a way that's detailed but not TOO wordy or confusing has been plenty of practice over the years.

Personally I would take it for a run first and get it hot and then check the water temp in the top tank with a radiator thermometer, if its hot enough then I'd leave well alone.

I had an Au when it first came out and it too sat exactly where yours is, even when towing a trailer it never went over the O. Gave it to my son and they had it 8yrs. I wouldn't worry about it.

Thank you all; Ford Australia Forums said there is an optional "high flow" thermostat that can cause cold running like this. so either way it sounds like a new thermostat is my first stop. Will report back with results in due course.

Results:

franc123 was spot on!

Replaced the thermostat with a new Tridon aftermarket one (all that our local Ford/Mazda parts place stocks.)

The old thermostat wasn't jammed open, however it was a completely different unit than the new one, with a much bigger housing for the spring, marked "Waxstat made in England" on the top and 92 degrees on the bottom (new one is 82 deg which I understand is the correct temp.) Old one must have been stuffed as it was clearly opening at some much lower temp than the brand new one does.

The running is now much more like what I would expect. The engine warms up from cold quicker than before, heater blows noticeably hotter, and the temp gauge cycles between the middle of the "N" and a spot halfway back down from the N to the tick mark at the bottom of the normal sector.
(I managed to briefly get it up as high as the O in Normal taking her for a blat up the Martinborough-Carterton Road today with the air con going and driving as fast as conditions an the law permitted. )

Thanks everyone for your input!

great news for 2 reasons, first that your problem is sorted
& second, for the update, so many people come on here asking advice then never to be heard from again.

The least I can do to repay free advice, is provide confirmation that the advice was correct!

Have a au3 owned for last 5 years my temp sits on N as well with out any issues ,Heard its normal to sit there