(ET) Intermittent loss of top speed

[Thon Basom <tbamc gbta net>]

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 


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