RE: More headlight talk

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

Well, when I put the relays in on my ur-q (similar situation) I'll try to
find a place where there is a reasonable amount of room away from the
exhaust system, and preferably in a place where it will not be likely to be
damaged should the car be involved in an accident (due to the risk of
causing an electrical fire).  There's a lot of room in the area in front of
the radiator, but I'm not sure that it is safe enough for me.  Richard
Funnell mounted relays there on his urq ... and it took a hit in that area
without getting damaged.  I am also concerned about corrosion with things
mounted under the hood, so I'll probably use an old ABS box (from an old 5k)
to mount the relays and fuses in.  I like the idea of an ABS box because it
is sealed and the terminals are rated for high current.  One benefit of
doing it this way is that you can build the relay and fuse circuits on a
bench and all that you'll need to do in the car is the wiring ... when all
is ready you can simply connect up the relay box.  

You'll want to run a heavy gauge wire from the battery or alternator to the
relays.  If you use a box as I recommended, you might simply run 2 or 4
smaller gauge wires from 4 pins on the ABS box to the power take off.  You
may want to consider using one of those 80A fusible links that people are
talking about for the rad fan close to the point where you attach the power.
This would actually provide a measure of protection in an accident should
you damage the car in a way that shorts the relays.  

There is little need for any more than two relays ... one for the low beams
and one for the high beams.  You can get 4PDT relays with 20A per contact,
which means that you can power 4 individual bulbs for the high beams.  The
low beams would only need a 2 pole relay.  You should install fuses in the
lines from the relays to the individual lamps ... Radio Shaft has a nice
sealed, blade-style fuse holder that can handle up to 30A, or you might try
to find a mounting plate that can hold a number of fuses.  

Fortunately you car does not have the headlight circuit monitor for burned
out bulbs, so all that you need to do is to wire the relay coil for the low
beams to the point where one of the low beams was attached originally, and
do the same for the high beam relay.  One big side effect of doing all this
is that you will be eliminating the high current load that passes up the
steering column to the headlight switch, meaning that the switch unit is
likely to last a long time.  

I don't know if your new lights came with sockets or terminals, but if not,
you should consider replacing the socket rather than reusing the ones in the
car.  If you think about the fact that the current sockets are 18 years old
and exposed to heat and the elements, they would certainly be the weak link
in your new system.  Even a slight increase in the contact resistance can
lead to heating and meltdown ... which will damage your new lights as well
as the socket.  If your new lights are significantly higher power than the
OEM this is a must, and you should actually get ceramic sockets to handle
the heat.  

My final comment is not to neglect the ground wires.  Find one or more good
points on the body of the car that you can wire the grounds for the lights
to, and use the same wire gauge for the ground as you used to power the
lights.  I personally like to use star washers to ensure a good connection
to the chassis, and I sand a small area down to bare metal where the lugs
will attach.  After assembly, I coat the whole thing with dielectric grease
to try to minimize rust and corrosion.  

HTH!
Steve Buchholz
San Jose, CA (USA)

> -----Original Message-----
> 
> Anyway, I have learned that stock wiring just doesn't cut the mustard.
> So what do I have to do, I know how to do things, but in this case, I
> have to admit that I am not very professed. Where do I install the
> relay, if needed and what wiring setup am I aiming for. How is the
> switch going to work etc.