Maytag MFR Series Service Manual page 41

This does not prove there is power available
at the terminals, just that the control board is
attempting to turn on the relay. The control
board tells the relays to turn on via a wiring
harness. If the LEDs do not light, and the
controls are programmed correctly, the first
thing to check is this wiring harness, at both
ends, because these LEDs will light up even if
the fuse is blown.
160ma
Fast Blow
Fuse
Control Signal Input
Wiring Harness
3-13
On MC5 controlled washers there are no
relays or transformer on the signal board.
The supply voltage is all internal and comes
directly from the main washer control
board. If the LED lights, it indicates that
the corresponding chemical signal is being
powered with 24VAC. External voltage can be
used, but the connection has been moved to
the main washer control board.
MC5 Control
Board
MC5 Signal
Board