Re: (ET) can't get out of 1st speed

["Briggs, Michael" <Michael Briggs unh edu>]

Larry,

Actually, your message reminded me that I had already done those tests 
this weekend. With the tractor in neutral, it seems to go to full speed no 
problem. That's further making me think that it's just a low voltage 
issue, since in neutral the drive motor pulls less current (so less 
voltage drop). I started out mowing last weekend with a battery pack that 
wasn't fully charged, so perhaps that's the only issue. 

Thanks!
Mike

________________________________
Michael S. Briggs, PhD
UNH Physics Department
(603) 862-2828
________________________________

________________________________________
From: Larry Chace <RLC1 etnainstruments com>
Sent: Thursday, September 29, 2016 10:34 AM
To: Briggs, Michael
Subject: Re: (ET) can't get out of 1st speed

Hi, Mike.  With the gearshift in neutral, move the speed control
slowly forward.  Do you hear a nice big CLICK when the motor starts
up in 1st speed?  That is the "L" contactor turning on to provide
power to the drive motor armature.

Do you hear a second CLICK as you move the control into 2nd speed
position?    That is the "1A" contactor turning on to short out the
first "toaster" element, raising the motor armature voltage by a few
volts.

How about another one when you move into 3rd speed position?  That
would be the "2A" contactor turning on to short out the second
"toaster" element, raising the motor armature voltage to the full
battery voltage.

A lack of those big CLICKs indicates either a contactor failure (an
open coil) or a problem with the (in)famous Card #1.  You can check
the voltages on the contactors coils;  you should get 0v or "36"v
(off or on).

You might also check the slip-on edge connectors on Card #1.  If they
aren't making good contact, then power might not be getting to the
contactor coils.

There could also be a failure on the card itself,  but I'd look at
the conectors.

Larry Chace, I-5 and E15