Early 12v BMW 2002 High and Low Beam Relay Wiring Directions
Untitled Document
Early 12v BMW 2002
High and Low Beam Relay
Wiring Directions
As 2002 owners, upgrade
lighting systems that include additions of driving lights and auxiliary gauge
panels, upgrade of sealed beam headlights to H4s, and dash lights to PIAA
5w super whites, the stock relay and switch configuration also needs upgraded.
There are options
in upgrading the relay and switch system. One option is to purchase an upgraded
harness (#30815 - For H-4 halogen lights, #30816 - For H-4 halogen lights
w/HB5 bulbs) from a supplier like Painless Wiring (http://www.painlessperformance.com/catalogframe.htm).
The other option is to purchase components and build the harnesses. The home
built system costs about half of the packaged unit but requires a couple of
hours of fabrication time plus some basic knowledge of soldering and insulating
connections.
For clarification,
the early model 2002s low beam circuit does not have a relay but it is fused
in the stock fuse block on number three and four. The high beam circuit does
not have a relay or a fuse.
This procedure includes
instructions to add two relays to the early model 12v 2002s for high and low
beams. Some suggest the addition of relays will improve light output by 10%
-15%.
Listed below are
the needed parts. The part numbers listed are Susquehanna Motorsports (610.944.3233
or http://www.susquehanna.com/susq)
part numbers. Note: Susquehanna’s web site has a good tips section on wiring
schematics, which I took much of my information from, and the site has a section
on wire selection. Dave at Susquehanna is a wealth of knowledge and very willing
to help.)
Parts List:
From Susquehanna Motorsports
- 2 - relays #87483 ($10.16 each)
- 2 - relay base kits #87123B (includes
the crimp connectors #87272) ($2.56 each)
- 2 - H4 adapters #66490 ($7.85
each)
From Radio Shack or other supplier
- 1 role - friction tape
- 7 colors of 14 gauge primary wire
(fewer colors may be used, careful tagging of the wire is crucial. You may
notice in the schematic and photo, I only used five, wish I had used seven)
- Solder
- Shrink wrap tubing
- Zip ties
- Dielectric grease (Permantex 67VR)
- Connections to 12v power and to
ground. (The type connections depend on owner's preference and particular
configuration.)
Tools needed:
- Soldering iron (I prefer the new
butane units available at Sears or Radio Shack)
- Crimpers - this a specific tool
to crimp the connectors used on the relay base ports. Radio Shack #64-410
- Wire cutters and strippers
- Needle nose pliers
- Jewelers screw driver or small
pic.
- Helping Hands Wiring Vise from
Radio Shack helps to hold the wires while soldering, convince your wife, or
bribe your kid to help.
Assembly instructions
Determine mounting location
for relays. This location will determine the lengths of wire needed.
Cut the three wires
on the H4 adaptors halfway between the male and female ends. Now you will have
four adaptors, two female adaptors and two male adaptors. You will not use one
of the male adaptors in this procedure.
Assemble the harness
for the right headlight assembly:
(I chose to ground the
headlight assemblies on the driver’s side inner fender well. They can be grounded
at other places. The ground point chosen determines the length of ground wire.)
Solder lengths of wire
to the three leads coming from the female H4 adaptor. The leads from the connector
are yellow, white, and brown. The brown wire (on the left side of the connector)
is the ground. The yellow wire on the top of the connector is the low beam.
The white wire on the right side is the high beam.
Insulate the solder
connections with shrink-wrap tubing.
Wrap the harness with
friction tape.
Assemble the harness
for the left headlight assembly. This procedure is exactly like the right
harness, but the wires are shorter. Hold off on wrapping the harness. You may
want to include the next step in the harness too.
Assembly of the harness
that will switch the relay:
This next step is assembling
the two wires that “switch” the relay on and off.
On one of the male H4
adaptors, remove the ground connector from the plastic base. This is done by
inserting a small jeweler’s screwdriver or pick in the top of the base and bend
back the small barb that holds the connector in the base and pull out the connector.
This is easy as long as you insert the screwdriver in the correct place.
Now you have an adaptor
with two brass connectors not three. Solder lengths of wire to the yellow and
white lengths of wire that were on the H4 adaptor. Remember the wire you solder
to the yellow wire, it will terminate on the low beam relay point 86 and the
wire you connect to the white wire will terminate on the high beam relay point
86.
Insulate the solder
joints with shrink-wrap tubing.
Now you can wrap this
harness with the left headlight harness in friction tape.
Connections to the
relays:
Ensure you know where
you will install your relays in your car so you will have sufficient lengths
of wire in this step.
Cut the wires the proper
length to terminate into the relays and to reach whatever ground point you will
use.
Note on grounding.
As 02 owners know, grounding is important and we often have to remove things
as we work. I chose to terminate my wiring to the one of the screw holes that
holds the stock tii air-box on, but you will need to determine your grounding
point. I also used separate ground wires for the four grounds you need, one
for each headlight assembly and one for each relay. I terminated these on the
body with short pieces of wire, ring connectors, and spade tips. Then I used
insulated spade tips and short pieces of wire to terminate to the relays and
placed insulated spade tips on the ground wires coming from the headlight assemblies.
You may not want to go through all of this for the ground, your choice, just
get good grounds.
Now, it is time to connect
this nest of wires to the relay bases. Take your time and get rid of any distractions.
As a review, connections to these relays are:
- 30 – from battery power
- 86 – from switched power
- 85 – to ground
- 87 – to headlight assembly
- 87 – to your other headlight assembly
Crimp the spade tip connections on
the wires; you should have 10 wires to connect to the two relay bases.
Mark one relay base, high beam
and the other low beam.
You are making the connections into
the relay bases by snapping the connectors into the bottom of the bases. Later
the relay will push into the top of the base. Before you snap any of the connectors
into the base, set the relay into the base and somehow, make note of which hole
in the base corresponds the number on the relay, take your time and get a
good system going. This is important.
Disconnect the battery!
Connect the three wires from the
right headlight assembly:
- connect the wire from the low
beam to the low beam relay base, point 87,
- connect the wire from the high
beam to the high beam relay base point 87. and
- connect the ground wire.
Plug the H4 adaptor into the headlight.
Connect the three wires from the
left headlight assembly;
- connect the wire from the low
beam to the low beam relay base, point 86,
- connect the wire from the high
beam to the high beam relay base point 86.
Plug the new male adaptor into the
female plug previously connecting the driver’s side headlight. You may use dielectric
grease on the metal connections. Tape the connection to ensure it stays together.
Connect the ground wires, from point
85 on both relay bases, to a ground point.
Connect battery power to point 30
on both relay bases.
Installing the relay bases and
relays:
These bases “gang” together so only
one screw is needed to secure the relays to the car. If you reference the picture
of my installation, the third relay is to my driving lights, it wires in the
same manner as the headlights.
Install the relay bases to the car
with a sheet metal screw.
Then check the lights and hope for
no smoke! If smoke comes out, you cannot put it back in.
Please verify all
of these directions and connections; I am neither an electrician nor a technical
writer.
Bill Williams
|
