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Re: (ET) Tractor back up, now to figure out the high speeds....



Still not sure what the penthouse is (magazine?). If you're asking if the E20 has 3 wires going into the resistor array on the front or four, it has four. There are three speeds with armature in series with 3,2,1 straps, one full power speed (4), and 4 field weakened speeds. The main purpose of card 4 is to provide diodes, detect speed 4 for cruise control, and drop in the four FW resistors for speeds 5,6,7,8 and bypass speeds 6,7,8 if the shunt current is too high.

Reading the schematics it looks like speed 5 should be disabled if in reverse because the F/R switch has a second set of pins that basically short the bottom of the field through the F/R switch. That would lock out all the resistors in reverse.

Forward is a bit more interesting: Technically the field should not be bypassed by the F/R switch yet in my case speed 5 is. However if I disable the FW relay (so it doesn't lock out the high speeds) I get speeds 6,7,8 but *not* 5. No idea why yet.

Maybe something is shorted/open/weird with the forward/reverse switch. It's possible, that could also explain why the reverse light is on all the time now that the diode is fixed.

Hm. Note: Advice to "Get an Alltrax" will be giggled at. :-)

Chris


On 6/14/2015 9:01 PM, RJ Kanary wrote:
My numb fingers have struck again. :(

       Eight speed tractors have four wires going into the Penthouse
instead of three. You will notice the material over the limiters is
shaped differently /than/ the seven speed tractors.That's where the
MONSTER limiter lives that /allows /a smoother launch.


        It's basically different. :)

RJ

On 6/14/2015 8:08 PM, CZ wrote:
On 6/14/2015 6:23 PM, RJ Kanary wrote:
There are three armature limiters in the Penthouse, correct?

I don't understand: It's an E20 AA. Pretty basic little thing.

C







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