not getting a microamp reading

vn45

I have a trane roof top unit that is going off on flame sensor. I checked microamp read and was not getting one reading was 0. replaced flame sensor but not with OEM part and still not getting microamp reading. when checking microamps im putting my meter in series with flame sensor and i do have flame. Why am i not getting a reading?

snapperhead

all voltages need to be read in parallel even micro/milli like when your reading line or 24Vs....need to go from the contact point at the end of the sensor to ground...light up a torch or one of those plastic lighters...to het the sensor up