I believe that when a beast master goes unconscious the pet can still take an action freely. So my question is if the the battle smith goes unconscious then does your steel defender able to take an action while you are unconscious?

Unlike the Beast Master, your defender is not a living creature capable of thought. It's a construct that follows your commands.

The Beast Master rules state specifically:

If you don't issue a command, the beast takes the Dodge action. Once you have the Extra Attack feature, you can make one weapon attack yourself when you command the beast to take the Attack action.

If you are incapacitated or absent, the beast acts on its own, focusing on protecting you and itself. The beast never requires your command to use its reaction, such as when making an opportunity attack.

So while you're conscious, the companion will do one course of action, but while you're incapacitated (unconscious), it will make the decision to protect you and itself.

The artificer rules say, simply:

It can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take one of the actions in its stat block or the Dash, Disengage, Help, Hide, or Search action.

Because it's a construct, I would rule as a DM that it cannot think on it's own to do anything other than that. Because you are incapacitated, you cannot use your bonus action to command it to do anything more than it would do on it's own.

Hope that helped.

Sure did.Thank you!

Of course that may change during play if you DM allows your Defender to gain intelligence. Or if s/he allows you to eventually program contingency Actions into it.

The more I think about it the more it would make since not to allow it. Do to arcana jolt allowing the defender to heal would mean this would be the only class that could pick themselves up while unconscious. Which if allowed may not be to strong seeing how it can only be used 5 times maxed. This would make for a good solo person if allowed but could be a bit to strong of an ability in a group. Not sure which way I lean atm.

I disagree entirely. A construct is still a creature, and sentience is based on intelligence. By design, no it cannot take any action besides one you command it or the dodge action, however it can still use it's reaction as normal and move, even if you're incapacitated. It's int is actually 4, which makes it ever so slightly self aware. Also, amazingly it says nothing about bonus actions. By default, it doesn't have any...

So here's what you do to make your construct "sentient". Since it is still classified as a creature, it can attune three magic items. So, first of all, you give it a circlet of intellect giving it 19 intellect. Then, you give it a belt of dwarvenkind to allow it magically to speak(and take dwarven yourself so you can translate). Then, you give it a dancing sword with the command word in dwarvish, and cast enlarge/reduce on it. 

Then you mount it and ride your now sentient speaking steel defender with a sword it uses as a bonus action into battle, all within the rules. After some time you start a cult around your defender, maxing out your deception stat and disguising or illusioning your defender, and claim to be it's simple messenger and translator. All hail Lee the mechanical lion god of War.

Then finally question who the real defender is

Yay for magic.

Now that you went full necromancer on this thread, it's worth mentioning that the changes in Tashas now explicitly allow the steel defender to act freely while you're unconcious, so give that steely boy a potion that they can give you.

Also I'd dissagree that sentience is mainly based on intelligence. But let's not talk about that.