I heard the 'contactor' "clattering" too, but mine turned out to be the speed control lever bouncing in it's slot. . .
Now, to test that contactor to see if it is dropping. . .
Get a volt meter with alligator clips on it. Put one lead on each side of the high speed contactor on the small lugs. Read the voltage. With the tractor not moving (but on), it will be 0V. When the contactor activates (tractor moving and in high) it will go to 36V0v or very close. Run the tractor and see if the 'dropout' occurs and watch the voltmeter. If the drop happens the voltmeter should show 0V or close. If the voltage does not change by much while the drop is occurring, the contactor may be bad. If the voltage does change while the drop is occurring, it may be the connection on the controller board. Those are just a rinky-dink connector stuck onto the board and it may be loose. If one or more are loose, very carefully squeeze it to make it fit tighter and try again.
Let us know what you find out!
Have a GREAT and ELEC-TRAKifying day!
Doug
My 12M has started intermittently losing top speed in both 3rd and 4th gear. It will be mowing along normally and suddenly the speed will drop into what I presume is speed control position 2. A few to maybe 20 seconds later will abruptly return to top speed. My initial guess is that perhaps contactor 2A is weak and dropping out? If that’s likely how would I test it, as it’s intermittent? I’ve had problems in the past with switch 2A going bad, but that’s always been when I was unable to get into top speed, not when already there. Not sure if it could cause this scenario? Don’t know if it’s relevant but for a long time I’ve heard what I presumed was a contactor clattering (no change in speed) when going over bumps when driving down the road. Thought that might be normal, but maybe not? :-) Suggestions? Thanks Thon -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://cosmos.phy.tufts.edu/mhonarc/elec-trak/attachments/20260624/4dbf88e4/attachment.htm> _______________________________________________ Elec-trak mailing list Elec-trak@cosmos.phy.tufts.edu https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak