(ET) Reverse Relay

[Michael S Briggs <msbriggs alberti unh edu>]

Ok, here's part of the problem I'm running into trying to figure out this 
"tractor won't go forward" problem - the schematic of the reverse relay in 
the service manual (page 5-26) shows it having 6 poles, with wires 6, 49, 
and 11 connected on the left, and 11, 10, and 6 on the right. Based on 
the schematics showing how the field works, my understanding is that when 
you have the speed selector in forward, the relay has wires 6 and 49 
connected (presumably making that connection on the left side of the 
relay) and 10 and 11 (presumably on the right). When you move to reverse, 
it closes those connections, and connects wires 11 and 49 on the left, and 
6 and 10 on the right, making the field current go the other way across 
the field coil.
	Here's the problem - the relays in the tractor have EIGHT 
connections, not six. So, what are the other two? The numbers of the wires 
aren't visible where I can see them on most of the wires, so I was hoping 
to just determine which wires are which (and which should be connected 
through the relay when I want to go forward, to determine if the relay is 
fine) based on the schematic in the book showing six connections on the 
relay - but there are two extra. So, what are they, and why doesn't the 
service manual show them?

Thanks,
Mike

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