I need help tracing an intermittent short.
Twice in the last couple of days my '70 TR6 has blown the main
switched-power fuse (TR6's only have 3 fuses). This runs brake lights, turn
signals, instruments, radio, and most things that have switched power. The
first time it blew, I replaced it with my spare, and it got me home, but when
I took a look it showed signs of heat, and (molten) solder had dripped out of
one end. The next (short) trip it survived, but this morning it blew again.
So, I have an intermittent short somewhere (oh goody). Any good
tricks on tracking this sort of thing down? I'm pretty sure it's not the
radio, though the wiring is a bit of a hack job by the DPO (I checked that
first). I was on the brakes both times it blew, so that's a candidate. Turn
signals weren't on, so that's unlikely (though it could be before the
switch). Of course, I'm now out of the correct fuses. I may use 15-amp
american fuses for debugging (the "35-amp" Lucas fuses are slow-blow 17-amp
fuses - 35 peak, 17 continuous - from what I understand).
This is doubly annoying since I finally fixed the last major thing
that was broken when I got the car - the hazard switch. (TR6 hazard switches
tend to either oxidize and fail or (as in my case) the grease cakes up and
doesn't allow contact. And new ones only cost ~$60.) Luckily, they're
easily disassembled and cleaned - though getting to them is a pain (speedo or
tach, take your choice).
While I was in there, I took out the wiper switch (only low speed has
ever worked, and no parking - the Clear Hooters wiper switch tends to die,
and the only replacements aren't even the same size.) I was going to put in
the lucas replacement, but then I saw what "a little filing" meant. That
encouraged me to bring the old switch back to (partial) life by switching
it back a forth a lot. I got all circuits in the switch to work, at least
for now, though once back in the car high-speed still doesn't work (it may be
the motor). Park works now, at least for the moment.
--
Randell Jesup, Scala US R&D, Ex-Commodore-Amiga Engineer class of '94
Randell.Jesup@scala.com
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