Headlight Switch Burnouts Eliminated

[BobB]

Referring to the starter switch and the high/low beam switch on a
Valkyrie Standard or Tourer.

While it was raining all Memorial Day weekend I installed the my complete solution
to the Valkyrie's starter switch and high/low beam switch burn out issues that cause
the headlight to go out.  The original wiring to the 55/60 watt bulb on a Standard or
Tourer has all the current of 5 amps passing through these switches.  I was running
a 90/100 watt bulb, increasing this amperage to 8.33.  After several years, my
high/low beam switch failed and my starter switch was also failing.  Refer to the
thread http://www.valkyrieforum.com/bbs/index.php/topic,55293.0.html for
the history.        

Protecting the starter switch involves the use of a 4P relay that channels the power
to the headlight through the relay contacts and reduces the current through that
switch to a fraction of an amp.  This solution has been around in the Valkyrie
community for some time.  However my issue was at the left handle bar, the high/low
beam switch.  Protecting that switch involves the additional use of a 5P relay that
also channels the power to the headlight through this relay's contacts and also
reduces the current through that switch to a fraction of an amp.  
Refer to the wiring diagram below.  

All of the alterations are contained within the headlight housing of my '98 Tourer.
I made use of "Micro ISO" relays because they are 1/2 the physical size of the normal
relays we find out there.  They are intended to be used in the under the hood
electrical housing on cars.  These relays are more expensive but were found to be
reasonable on eBay.  The relays are pictured on the wiring diagram below.  I found
that the coil resistance on these relays to be around 80 ohms yet they had a 30 amp
contact rating.

I created a relay sub-assembly with the two relays side by side.  Tape them together
with with 3M auto molding tape leaving a 1/8" gap between them to allow for the curve
of the headlight housing.  Solder a short, 10 amp capacity, jumper wire from one of
the 4P relay contacts to the common 5P relay contact.  Solder a 1 amp capacity green
wire between the one side of the two relay coils and continue that wire out for 10
inches.  Solder a 1 amp capacity 10 inch wire to the other coil side of the 5P relay.
Attach a 1 amp capacity 10 inch wire to the other coil side of the 4P relay with a
female spade connector.  Use female spade connectors to attach 10 amp capacity 10 inch
wires to the remaining three contact connections.  When complete the relays and
soldered joints should be sealed with silicone and let dry over night.  
This sub-assembly was mounted on the inside top of the headlight housing, just in
front of the indicator lights using the 3M tape.

The sub-assembly has six wires exiting:
- A relay coil ground wire that is soldered to one side of both relay coils.
  It carries a maximum of 0.4 amps and gets connected to the green ground at the
  H4 socket.
- The 4P relay coil trigger wire, with a spade connector.  It carries only 0.2 amps.
  This is tapped into the single connection, blue/white wire, coming from the starter
  switch and heading to the high/low beam switch.
- The 5P relay coil trigger wire, soldered in place.  It also carries only 0.2 amps.
  The white and blue wires at the H4 socket are both cut and this wire is connected to
  the white wire coming from the high/low beam switch.  The blue wire coming from that
  switch is insulated and is no longer used.  See note below *.                
- The other 4P relay contact is connected to the relay with a female spade connector.
  This is tapped into the primary headlight power feed, black/red, near the
  8-pin socket.
- The NC 5P relay contact is connected to the relay with a female spade connector.
  It is soldered into the white wire, low beam, at the H4 socket.    
- The NO 5P relay contact is connected to the relay with a female spade connector.
  It is soldered into the blue wire, high beam, at the H4 socket.

* Note: This circuit has the normally closed (NC) contact of the 5P relay supplying
           power to the high beam.  When the 5P relay is triggered by the white wire,
           power will go to the low beam.
           It is wired in this manner because I run headlights on high beams 98% of the
           time, only possibly using low beams when riding at night.  So, most of the
           time, no current passes through my high/low beam switch and less than 0.2 amps
           passes the starter switch.  I use a Kisan Path Blazer that flashes the
           headlight in the daylight but it only operates on high beam.  If this is not
           how you operate, the blue and white wiring connections from the 5P relay can
           simply be reversed and the 5P relay can be triggered by the blue wire.

Circuit diagram and relays.


Finished view inside housing.  4P relay on the left, 5P on the right. 


Closeup of the H4 socket.


Hope this helps other VRCC members out there.

[pancho]

Good job Plunker,,, good info and a nice writeup.

[Gryphon Rider]

Putting relays into the circuits the way you have is an excellent idea, especially when using a higher-than-stock headlight bulb.  There are a few of things I'd like to mention, one of no real consequence and a couple worth considering when designing your circuits and selecting relays.

First, of no consequence, is that when you say "4P" relay, we electrical types think "4 pole", not "4 pin". Your 4P relay is known as a NO (normally open), a.k.a. Form A relay. The other one is known as a CO (changeover), a.k.a. Form C relay.

Second, when selecting a relay, take a close look at the current ratings of the contacts. You will find that they are rated differently at different temperatures (lower ratings at higher temperatures), and with Form C relays, the NC contacts typically have a lower rating than the NO contacts.  You have used the NC contacts to switch the higher current high beam, and you have the relay in the headlight housing, which can probably get fairly hot. If the relay does fail, switching it out will be more difficult with the soldered connections.

[F6MoRider]

Have you thought about posting or getting this posted to the SHOPTALK section of www.valkyrieriders.com? 

Might be beneficial there as it will get buried in the message section as new posts are added. 

[gordonv]

I made use of "Micro ISO" relays because they are 1/2 the physical size of the normal
relays we find out there.  They are intended to be used in the under the hood
electrical housing on cars.  These relays are more expensive but were found to be
reasonable on eBay.

My first thought when you mentioned found in cars, was the auto wrecker. Should be really cheap there.

How much $ where they on ebay?

[98valk]

all about relays and other wiring for our bike

http://www.rattlebars.com/valkfaq/circuits.html

I used the conduct tite for my headlight, I think it was Mark T who had used them with instructions on his site at one time. 
one of two failed after about 5k miles replaced it and now 25k later no problems.