Re: (ET) Intermittent loss of top speed

[Rob Brockway <getractor yahoo com>]

 I would see if you can put it in neutral and check to see if there is a 
voltage drop across the control resistors when the speed drops.  This will 
tell you which contactor is failing.  You can then check to see if the 
contactor has voltage on its coil.  This way you can trace it back and see 
if it is the contactor or a micro switch in the speed control etc.
    On Wednesday, June 24, 2026 at 02:27:27 PM EDT, Thon Basom <tbamc gbta 
net> wrote:  
 
 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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