Onan 10K QD Code 45- Speed sense fault issue

Ivylog wrote:
Did a search on here and came up with 15 hits, one of which had this:
The service manual code 45 has the following diagnosis.
1- Service the brushes and slip rings as necessary. and test the generator field and quadrature windings for open shorts. replace a rotor or stator with faulty windings(the quadrature windings provide the speed sense signal
2- replace controller.

..........Or this:
look above the start stop switch on the genset part that looks like a beehive.
remove the 10mm bolt which holds the square plastic piece with 2 wires.

remove the brush block and check the brushes are they free to move in and out?

does one look smooth on the end and the other look rough or burnt?

look in does the brass slip rings look smooth with a black line where the brushes run or does it look burnt+pitted?

if you put a multimeter on ohms and touch it across the brass slip rings does it read 31.9 ohms?

if you touch a slip ring and the genset housing does it read 0 ohms?

remove the 10mm bolt under the start stop switch and raise the front cover off
look for two wires with plug in crimp connectors labled Q1 and Q2
unplug and ohm these wires in the directon of the genset not to the controler(big red plug)
you should read 2.42 ohms


look under your genset for a black rubber plug left rear on the bottom
remove this plug and use a socket and extension to turn the bolt on the bottom of the rotor

when rotating clockwise do you feel the engine turning over?

do you get resistance as the engine hits compression?

does it feel like it slips or powers the engine throight the compression stroke?
if no to above the coupler is broken
the genset will have to come out and be removed from the base to change the coupling. also check the bearing in the pulley if it does not fit tight on the flywheel stub it will make a knocking noise and cause the new coupler to fail.


Sounds like some emery cloth under the brushes might solve the problem.