740 side markers

When installed, are these supposed to be on all the time and blink alternately with the front turn signals?

No. factory installed versions are off normally and blink only when the turn signals blink.

You can certainly install them as you described and many people prefer to do it that way.

I have them installed, the side markers are on as daytime running lights. as well as they blink alternately with the turn signals. not sure if thats normal or I did something wrong.

You have done what a lot of people prefer to do, but it is not how the cars are set up from the factory. I wouldn't call it wrong, and many people think of it as safer because your side marker light serves as a running light from the side and still flashes as a turn signal. Stock setup is dark unless it is flashing with the turn signals.

I would guess that you added side markers with some scotchloks and tapped into the turn signal wire and the parking light wire (instead of the ground wire). So you get running light when the turn signal is off and it flashes alternately with the turn signal. If you want them to just flash with the turn signals then you need to remove the connection to the parking light wire and move it to the ground wire or ground it to the convenient ground terminal block on the fender with a spade connector.

Here is a good explanation of what you did by accident and many people do on purpose. It is the "Crossfeed Method" about 2/3 of the way down the page.
http://www.danielsternlighting.com/tech/markerflash/markerflash.html