[TR] TR3A Fog/Spot Lamp wiring question #2

[Randall]

My preference would be to feed the new switch(s) from S1 of the original
headlight switch (taillight circuit).  That way, the fog & spot lights will
only work when the taillights are also on.  For me, it would also reduce the
chances of leaving the new lights on when parking the car, while still
allowing them to be on with the key off.

You could also get the power from A on the headlight switch instead of A1 on
the control box, if you choose.  That run of wire is plenty heavy enough to
handle the extra load, IMO.  Wherever you choose, though, I would definitely
put a fuse, fusible link or circuit breaker near that point.  If, God
forbid, you get in an accident and mash one of those lights, you sure won't
want the wiring harness burning up in addition to the front end damage.

Your wire sizes sound fine, although I might go to 12 AWG for the power legs
if it wasn't too much hassle.  I have on occasion been known to install
higher power bulbs.

Relay location is mostly personal preference.  Unless you are using
period-correct relays (an original installation would not have used them at
all), it's probably best to hide them either under the dash or under the
front apron.  Either way, I would make a small bracket to carry the relays,
get them wired and tested first, and then bolt the bracket in place.

-- Randall