[TR] TR3 Horn Relay Questions

[Randall]

> 1) NG from fuse box to C1 on Horn Relay mounted on 'tower' at 
> Passenger-side horn
> 2) NG from C2 Horn Relay to Passenger-side Horn
> 3) NB from Horn Switch (bottom of steering column) to W1 on Horn Relay
> 4) NB from Passenger-side Horn routed back through harness to 
> Driver-side Horn.

I'm not sure all the colors are appropriate, but that wiring will work.  I
found it simpler to leave the existing NG wires, and install the relay
between the NB and ground; but your plan will work.

> 5) Grounds are W2 on Horn Relay and each horn to body.

That part won't work.  Since W1 will be grounded through the horn button, W2
needs to get power from someplace.  If you were so inclined, this could be
switched power to make the horns only work when the key is on.  But it could
also be constant power, your choice.

> Next: Installing a relay for the headlights.  Looks like it 
> should go inline before the dipper switch - is that correct?  

If you want to use only one relay, then that would be the place for it.
However, that means you'll still have headlight current routed all the way
to the dipper switch (and flowing through the switch contacts).  It is
preferable, IMO, to use two relays and wire them after the dipper switch, so
the headlight current only has to flow through the relay contacts and not
any of the original switches.

In fact, this time around, I am going with four relays so that I can have a
separate fuse for each side of the car.  Back in 2001 I was going down a
mountain in the Rockies at about 80 mph when the fuse for the high beams
failed and left me totally in the dark.  Even though all I had to do was hit
the dimmer switch, the experience was still unsettling and I would rather
not repeat it.  You can see my first attempt here:
http://tinyurl.com/3yzdl9b
although I think I am going to rework it without the sockets and new wires
all the way to the bulb terminals.

> But where would it get the fused power (NU?)

You'll need to add a fuse (or two if you use my method), or perhaps a
self-resetting circuit breaker instead.  At the moment, I am using a TR6
style Lucas fuse block mounted near the control box, but my plan is to
switch to a pair of circuit breakers mounted out of sight inside the cabin.

-- Randall