6W 12V 5A peltier only drawing 1A, I am supplying more current but its only drawing 1A
For current draw, the peltier just looks like a resistor.  However, as it heats up that resistance increases.  So in order to get maximum current draw you need to keep it as cool as possible.
1.5 Amps still seems a little low, but these things are notorious for being specified poorly.  All it really does is move heat, the end result being a temperature difference between the two sides.  So the colder you keep the hot side, the colder the cold side will get.
Thermoelectric Cooling
The current is linear with supply voltage.  If you supply a higher voltage you will get a proportionally larger current and the temperature difference between the two sides will increase(not proportionally though).  If you exceed 80C or so on the hot side, your device will start to degrade.  These are just rules of thumb not knowing your exact specifications.