Do you have a DMM? (Digital MultiMeter)
If so you should be able to measure the 5s ON/OFF signal coming out of pin 25.
If so you should be able to measure the 5s ON/OFF signal on the Drian of the MOSFET.
How much current do you aim to run through the PTC?
The 1K resistor in series with the PTC will limit the current to 12/ 1000 = 12 mA.
P = V x I = 12 x .012 = 0.14 Watts.
Can you please post link to specs/data of the PTC?
Tom.... 
