Replaced soldering iron heater, now station going nuts

[Fallingwater]

I have a cheapo "Lukey" 936A station (the station itself, the iron). It's always been marginal - I have to set it to 480 for it to behave like my *good* station when I set that one to 300. Said good station recently died. I have a TS100 on order to replace it, but while it gets here I wanted to fix the cheap backup. As luck would have it I bought a pair of replacement heaters (allegedly Hakko A1321) when I got the station, so I disassembled everything and hit the first problem - the stock heater has two transparent wires plus a blue and a red one, while the replacement has two blue (sensor) and two red (heater).

I figured the transparent wires were the heater, but to be sure I plugged it in and measured VAC while it was running; sure enough, the transparent wires' pads read somewhere around 20VAC. There was apparently no VAC across the other two pins.

There was another problem: the manual of the A1321 said I should be reading 2.5-3.5 ohm across the heater wires and 43-58 across the sensor wires. This was consistent with my readings for the replacement heater. The stock heater, however, has a reading of 18 ohm across the transparent (heater?) wires and 1.5 ohm across the blue/red (sensor?) wires.

I was a bit puzzled and thought maybe the wrong readings were due to the stock heater being bad, so I swapped in one of the spares soldering the red wires where the old transparent ones used to be and the blue sensor wires to where the blue/red wires were.

Now if I turn on the station the heater LED only stays lit for a short while before switching off and only blinks every now and then. The heater itself gets to scalding temperatures *blisteringly* fast - like, a couple seconds; I haven't yet enclosed it all and tried soldering with it, because I'm worried I'm going to kill the heater. It appears to be *strongly* overdriven.

I assume the heater/sensor connections are right because there's no way the sensor itself would be able to heat up the ceramic if connected to the wrong pads (I imagine it'd just blow up), but then what about the ohm readings and the extreme amount of heat I'm seeing?

I've no idea where I'm going wrong. Little help?

[wraper]

You replaced heater with termocouple temperature sensor with heater which have thermistor sensor.

[sleemanj]

Chinese A1321, A1322 are different, ostensibky even to Hakko A1321.  Search forums for those model numbers it's been discussed in detail previously.

[Fallingwater]

I had no idea, thought they were all the same. Thanks. Back to the stock heater we go, at least with that I could solder *some* things. Can't wait to get the TS100, sigh.