[TR] Fwd: TR3 O/D Wiring question

[Randall]

> There is a descrepancy between what is on all three of my 
> wiring diagrams and how the harness is set up.

If you check the diagram at
http://tinyurl.com/l9jkj7
I think you will find that it matches your harness (and the original harness
on TS39781LO).  It works just fine.

However, I added a in-line fuse between the ammeter and C1, and also a diode
from C2 to ground.  The solenoid has two windings inside, and contacts that
interrupt the power to the high current pull-in winding once the armature is
fully retracted.  Without the fuse, the solenoid will quickly burn up if it
gets jammed (or badly misadjusted).  But with the fuse, the fuse blows
harmlessly, giving you a chance to correct the problem and reuse the
solenoid.

I used a MDL-8 8 amp "slow blow" fuse (mostly because it was handy), but I
believe an ordinary AGC-5 (or Lucas 10 amp) will also work fine.  (Early
Stags used a Lucas 10 amp for an A-type OD.)  Although the pull-in coil
draws close to 20 amps, it is normally so short that the fuse does not have
time to get hot enough to blow.

The diode greatly extends the life of the relay.  It's just an ordinary 1
amp 100 volt power diode like from Radio Shack.  Here's a shot of it
installed on TS39781LO
http://tinyurl.com/2dcppeo
Although the original relay lasted many decades without the diode, none of
the replacements I tried (including expensive reproductions from two
different major vendors) lasted more than a year without the diode.  But
with the diode, that cheap relay in the photo has worked fine for about 10
years now (and is still working fine in TS13571L).

-- Randall