I am looking for some "quirky" traditions that Jewish Orthodox
undertake. For example I know that they have special timers on lifts
on Saturdays...

Can you be more specific?  Pretty much every single detail in Jewish
law or tradition may seem quirky to those who've never heard of it.

BTW, you're confusing two things in your statement about lifts
(elevators). The Orthodox use timers on Shabbat to turn appliances on
and off. They also have a special setting for elevators to run
automatically, but it's not a timer.

Maybe if you could explain why you're looking for "quirky" traditions,
researchers can give you a higher-quality answer.

ravuri-ga

OK, I'm writing a book and one of the characters is an orthodox Jew.
I'm trying to beef up his character.

I'll tell you a few more things about him:

He is a caretaker in a Tel Aviv Orphanage
The "quirks" are to do with this job, namely cleaning, cooking, etc.

I hope this is a bit more specific & enough to receive the answer

Thanks

On the Sabbath (saturdays), toilet paper will be pre-torn into squares
so that no tearing takes place on the Sabbath. Paper will be torn the
day before.

Since you can not carry anything on the Sabbath, often your house key
is turned into a piece of jewelry. Women, for instance, will wear a
key that has been turned into a pin. Men will sometimes turn the key
into a tie clip. This way when they go to services, they can get back
into the house afterwards, without having to have carried something.
This is more common for the women, as they will get home first to
prepare the afternoon meal.

Oven are left on a very low temperature from Friday night through
Saturday, which is why it is common to eat stew-like foods on the
Sabbath. The button that turns the light on or off will be 'fixed' so
that it is inoperable. Or I've also seen where the oven light is just
left on for the entire time period, ergo opening the door doesn't
affect the light.

Same goes for the refrigerator, light button will be fixed. Some newer
refrigerators, even fancy Sub Zeros have what is called a Sabbath
mode, so that the light will not go on or off. KitchenAid ovens also
have this feature, at least the newer ones do.

I hope that these help.

I worked for an Orthodox Jew years ago and one
of my tasks was (as a non-Jew, at least at the
time, but that is another story) was to unlock
the building, turn on the lights, start all of
the equipment, etc. at his offices on Shabbat.

OK, here are two suggestions based on the job of your character.

Cooking: An Orthodox Jew has very strict rules about food preparation.
For example, an Orthodox cook would need everything in the kitchen to
be separated into milk and meat sections. (The Israeli army tries to
follow this rule, but not all the cooks are used to being so careful.)
If milk falls into a pot of meat and there isn't sixty (60) times as
much meat as milk, the food would have to be thrown out and the pot
"kashered" (made kosher in a specific way). Orthodox rabbis are used
to getting questions resulting from more complicated milk/meat
mix-ups. See, e.g., http://www.jewfaq.org/kashrut.htm

Cleaning: Before Pesach (Passover), the Orthodox clean their houses
and offices extremely thoroughly because the Torah forbids owning even
a bit of "chametz" (leaven) on Pesach. This rule lends itself to
neurosis and can lead to ludicrous extremes, which at least some
Orthodox rabbis warn against. See, e.g.,
http://www.aish.com/holidays/passover/articles/passover_cleaning_made_easy.asp

In general, http://www.jewfaq.org is a good introductory resource on
traditional Jewish behavior.

Caution: Make sure that someone Orthodox and knowledgeable looks over
the relevant parts of your book before you publish it. You don't want
to get caught in a mistaken detail that could make you look stupid.

For example, the description above by lstein0-ga about carrying on
Shabbat is correct, BUT also irrelevant in a place like Tel Aviv which
has an eruv (a situation in which carrying on Shabbat is okay without
following the normal rules). If you described your caretaker as
wearing a key-pin on Shabbat in Tel Aviv, that would just be silly.
The same goes if you made the caretaker some impossible combination of
dati-leumi and charedi, the two types of Orthodox in Israel, who are
very distinct social groups. (The writers of The Simpsons made similar
mistakes in portraying Rabbi Krustofski, Krusty the Clown's father, in
the episode Like Father, Like Clown.)

Good Luck,
ravuri-ga