(ET) E20: Better-ish but still weird

[CZ <cz alembic crystel com>]

So more work on the E20 today, specifically trying to figure out what's 
going on. It continues to be more weird, with the diode in the reverse 
light comes on all the time. I'm wondering if maybe the reverse switch 
has one of its' toggles stuck in reverse or something. That could do it.

The reason speed 5 wasn't coming in was because diode CR412 was blown 
and open. That kind of makes sense, without it the 36 wire from card 4 
going to the top of the field would never have had power. Which means I 
have been driving in speeds 1,2,3,5,5 all this time. Hm, no wonder the 
tractor would bog down going up a hill with the blower; I had the 
tractor running constantly with R4 in series with the field.

Oh well, live and learn. Now in speed 4 I get what felt like more stable 
speeds going around with CC on, however when I kick in speed 5 the CC 
relay stays sealed in (it does not drop out). Unless it's picking up the 
ground from R4 to ground, which is still enough to keep it from tripping 
out. In which case CC might be terminated by speed 6 or 7 which are not 
coming in because my FW circuit is still broken.

Hm. I think tomorrow I will try disabling the FW lockout coil to see if 
speeds 6,7,8 drop out the CC. And I'll try to figure out this reverse 
thing, what's making me wonder right now is does the tractor think it's 
in reverse somehow from a FW sense all the time, and that is the reason 
why the reverse light comes on *and* the FW relay is bypassing the 
resistors? Hm...

Chris