Working on a Whirlpool gas dryer model LG5551XTW0
. Customer complaint was runs but no heat. Pulled front to access burner & observe ignitor. Ran unit found no ignitor glow. Checked & found the following:
IGNITOR: Continuity - 72 ohms (within Whirlpool's noted range of 50 to 300 ohms)
FLAME SWITCH: Continuity - 0 ohms
CONTROL T-STAT: Continuity - 0 ohms, heater ckt good
THERMAL FUSE: Continuity - 0 ohms
HIGH LIMIT T-STAT: Continuity - 0 ohms
MOTOR SWITCH CONTACTS M1 - M2: Continuity - 0 ohms while running, wires disconnected.
TIMER CONTACTS: At R to B terms: Continuity - 0 ohms
So it seems as if the circuit is good and should provide power to the ignitor. Though this would not prevent the ignitor from operating, I also checked the coils on the valve and all show continuity. I then unplugged the wire to the burner assy and checked voltage with the unit running and found that (wires 1V to 3V) to be at 40VAC. That didn't seem right to me, so I manually bypassed each t-stat, the thermal fuse, the timer contacts and the motor switch one at a time and came up with the same results.
I must be missing something. Any ideas?