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

[Larry Chace <RLC1 etnainstruments com>]

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 at about 28v.

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 to about 
32v.

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 indicate speed control microswitch 
failure, a contactor failure (such as 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.

Look at the card to see if there are signs of trauma (like fried 
components).

There could also be an invisible failure on the card itself, but 
check the coils and the connectors first before thinking about 
replacing the card.

Oh, try the CLICK tests in reverse -- sometimes the microswitches' 
actuator buttons wear down, such that the switches don't switch. 
They and their cam plate wear more in the forward direction (since 
that gets used more often).

Larry Chace, I-5 and E15