Forward Lighting Systems
It was a dark and stormy night...we were trying
to stay on the twisty Sawmill Parkway in rush hour traffic. The four
weak headlights on our then 25 year old Plymouth Belvedere were not doing a
thing on the glistening slick pavement. I thought, boy, there has
to be something wrong here. I've learned
the answer is yes and no.
When I got my '67 Barracuda on the road I started to meet
rallyists at the local SCCA club. These are people who have to
have good light! A little later than sooner my Barracuda got
headlights and then a relay system. Newer vehicles aren't always
although the trend finally seems to be moving in the right
direction. When I got
my '85 Jeep Grand Wagoneer, I couldn't believe how weak the headlights
seemed. While it didn't as desperately need the relay system, I
installed good H4s almost immediately.
Nothing was actually 'wrong' with the lights, that's the way headlights were made.
Yes, there is a lot of improvement that can be had and its not hard to do.
For anyone thinking about
upgrades the basic issues and solutions are the same:
1. Provide adequate power to maximize the performance of the lights.
2. Use lamps that put the most light on the road with the least upward reflection.
reflector and lighting filament all combined in a vacuum sealed
unit. Works like an incadescent light bulb. Replace when
- From the 1960s through the 1970s, all US manufactured vehicles were
using sealed beams.
Halogen Sealed Beams:
Same as above but slightly brighter
because they are more efficient. Totally interchangeable with equivalent sealed beam.
-A concours restoration vehicle
would not want them because they are marked differently. Other than
that, they are more than worth the slight additional cost.
- In recent years some have been hyped (that
is marketed with unsupported claims) but there are some that seem
to be verified as better than others.
Bulb Powered Lamps:
consisting of lens and reflector assembly that uses a replaceble bulb,
usually an 'H4' or variant for the high/low beam.
- These came into use in the 1960s (but
not in North America) with UK approving the H4 for street legal use in
1969 and Europe in 1972.
- They are often referred to as 'E-code'
lamps as most were designed for European standards are so marked.
- Over the years there have been some
versions that also met and were tested and approved for US
standards. Now it seems most states will accept either.
- Generally they focus more light down
on the road and have a strong cutoff to reduce upward glaring light.
Most of the standard low beam/high beam lamps are
rated around 55 Watts/60 Watts.
Power rating is the power each lamp should draw
and does not directly indicate lighting power.
For the same
55 Watts, the halogen lamp will produce more light (see Lamp Efficiency
Similarly a good H4 bulb in a good lamp assembly
will put more light on the road for the same power as a sealed
halogen. They are also available in high wattage ratings.
All lamps will be brighter if they receive
full voltage. However, an H4 bulbs whose voltage drops below a
certain threshold will noticibly dim.
For the 1960s into the 1980s most European and American market automobiles used headlights of standard sizes.
In terms of size and shape there are two arrangements using round faced lamps, and two arrangements using rectangular lamps.
- Two 7" Round lamps combining high beam/low beam
- Four 5.75" Round lamps, two combining high beam/low beam, two high
- Two large rectangular lamps combining high beam/low beam. 200mm w x 142mm wide.
- Four small rectangular; two combining high beam/low beam, two high
The electrical circuits on many older American cars
weren't redesigned as more 'accessories' such as wipers and heater fans
were added. Perhaps to save money or weight, Chrysler
engineered their A+bodies with the minimum wire sizes needed to
carry the required current. The wires to the headlights are only 18 gage.
to carry the 10 amps that two 55/60 Watt lamps can draw. For
safety, they have a 15 amp (instead of a 20 amp) circuit breaker in the
switch. Even with 16 gage wire and 20 amp circuit
breaker, the headlight circuit of any older vehicle where oxidation,
heat and other wear has deteriorated the wiring can cause
resistance is most likely to be found in the connectors and
two things. First it causes a voltage drop. Lower voltage makes the lights dimmer. Second it draws
additional current into the circuit. Current passing
through an area of high resistance produces heat.. Watts =
x amps. While the circuit breaker may trip if the current
draw is high enough (either 15 or 20 amps) it doesn't take too many
watts to melt a plastic connector!
That can happen below the circuit breaker's rating. I've had both
happen with a-bodies....
Relays, a short path for a hot circuit.
Relays are remote switches. Send them power and
they turn a switch; Turn the power off, and they turn the switch off.
So, in a relay system power from the high/low beam switch is used to turn on the high or low beam relay. The advantage
is that a relay only needs a little current to be switched on.
Barely adequate wiring becomes overkill.
The real power for the headlights is fed to the relays directly from
the alternator (or battery)
using as heavy of a wire as required AND a circuit breaker or fuse.
Therfore, if in doubt of the wiring condition and not a concours
restoration, install a relay system. For those prefering a period
correct look the
system can be designed so the relays are hidden from the casual
observer. Alternatively, often there are kits and
even pre-made harnesses for specific vehicles.
Headlight Choices, or how not to get burned
to be difficult identifying factual differences in headlights.
Lots of marketing hype; Not much available hard
data to the public; Some experts unwilling to acknowledge a
degree of subjectivety in personal preferences.
Remember, its your vehicle and its unlikely any of these sales people
or experts have driven in your exact terrain, or have the exact same
personal preferences. However there are some scientific and
semi-scientific independent tests, and a number of real lighting
experts (professionals in their field) that post on Candlepower forums.
The LED Alternative:
LED headlights have reached a point of development that some are a real
alternative. Lamps that are legit have met minimum US
DOT standards and are so marked.
A big advantage of LEDs is the low current draw. If you like your
old vehicle of its classic look, LEDs are probably not for
you. This is because all of the LEDs point forward and can't look like a traditional lamp where the light is directed in part by the reflector. The light on the road is matter of personal
preference here as all legit lamps produce a legal pattern when aimed correctly.
Halogen Sealed Beams:
Some people are quite satisfied with these. They are sealed
from the elements and last a reasonably long time. I have
not personally bought any in years, but swapped the last set into my
NPS work truck. The GE Night Hawks seem to get the nod for being
noticbly better than the others, especially in the 7" round, by experts
on Candlepower Forums. See this post on Candlepower forums for example
For rectangular replacements for AMC Jeeps SJs and others originally equiped with 6052 lamps, it appears the GE Night Hawk H6054 is one of the few sealed beam halogens of this size that provides the full lamp power of the original 6052 and H6052(65/55 watts). Other H6054s use only 35 watts on low beam. That offsets any advantage of the halogen over a quality sealed beam 6052.
Hella Vision Plus. I've used these for about 20 years in
7" round on the Barracuda. Pretty Good. Not sure which bulbs are in now. The original
bulbs blew during a grounding short and were replaced, probably with Narvas. 'Virgil'
on Candlepower forums thinks this is a decent choice, maybe even better than other current production H4 offerings.
Note he that he points out they should be aimed to US standards.
The lenses on mine are chipped and I will be trying a set of the discontinued Cibie
z-codes in 2017..
Cibie E-code. I've used these on the Wagoneer for about 15 years
(Large rectangular, approx. 5x7"). Pretty good. Only thing
I don't care for is how brightly they reflect off of reflective
road signs. One got cracked and the reflector oxidized
slowly over 10 or so years. Some experts consider
these the best current H4 offerings.
Bosch H4. The only other manufacturer that seems to have some good H4 models. Like the Cibies, availability can be limited.
The four headlight systems seem to have become the most difficult to find good lamps.
A decent comparison of some headlights comes from "Hilldweller's"
testing on JK and XJ Jeeps. He's posted his results and photos on
the Candlepower and Jeep Forums.
Each test was done the same way. The Jeep is parked on the right
side of a 2-lane road; camera on hood in front of driver. Lux readings
are taken at 12" height from road surface at the edge of each side of
the road. Another reading is made directly in front of the
vehicle and for some lamps he measured the highbeam light at over
100 yards. The JK uses a 7" round lamp, while the XJ uses a
rectangular lamp. Below is a Summary Table of the Light
Some general conclusions:
1. The bulb can make a big difference. Compare the Hella H4s with two different bulbs.
2. Changing vehicle or lamp version can make a difference. Compare Truck lite in JK (7" round) vs XJ (Rectangular).
Links to Hilldweller's original posts with photos and data below.
CAUTION: Jeep Forums can be slow to load. High Speed Connection
or No-script recommended.
Wagner Sealed Beams (XJ)
Truck-lite LED, improved (XJ)
Cibie H4 Z-beams
Hella H4 with Phillips Xtreme+80
Hella H4 with Delta Blue
JW Speaker 8700 improved
The advice I got from the rally crowd was to save my
money and upgrade my headlights first to H4s. Only then should I
go for fog lights if I still needed them. It was good advice.
The H4 lamps put most of the light below the headlight height, and
if aimed right, very little will be reflecting off of the fog when on low
beam. Later I found this advice from Scott Harvey in
Sports Car Graphic (May 1967) page 70. Photo at top.
of European headlights have a very flat top cut-off on both beams.
These lights are as good in snow or fog as any fog light I have used.
Also, they have a relatively low current-draw, so their bulbs have quite
a long life. They are not sealed beam, so they continue to function
even if the lens is cracked. These headlights double as good fog-lights..." Full article now available as PDF
My Wagoneer came with Marchal fog lights. I
got one to work, but the lens and reflectors were shot. I have replaced
them with H2 Cibie Tango 40s. They put out a lot of light, but basically
support the light in the low beam area. Aardvark
intl. has graphics showing the light patterns (and dimensions) of each
of the Cibie auxiliary lamps. Let me know if you find the same for
any of the others (Hella, KC) and I'll add their links too.
In use the Tangos were somewhat
disappointing when combined with H4 headlamps. They might have been
useful with the stock sealed beams. With the H4s, maybe they
would have been useful in the worst fog, when one must crawl forward at
a snails pace. The relatively high mounting location
on the Wagoneer probably would not help with these particular
lamps. In any event, one had its lens crushed while the
Jeep was parked in the city. Off they came.
Daniel Stern has created a
chart showing the light output for each type of bulb, so you can determine
for yourself what is better. Lumens is a measurement of light, that's
what counts most. Watts is power consumed. So, notice that
an H2 bulb puts out 50% more light than an H3 for the same 55 Watts.
So, do you want a auxiliary lamp that uses an H2 or an H3?
The halogen bulbs do not work well if they do not
get adequate voltage. In other words, if they don't get 13.5 Volts,
they don't draw 55 Watts and don't put out the lumens listed. Below
12 volts, they are very unhappy. Stern also has a big chart of small
Virgil has posted some test results of H4 type bulbs on Candlepower forum.
Volts, Amps, Watts? Watts it all mean? Ye old electrical analogy:
Think of Volts like water pressure in a pipe or garden
hose (psi), and amps as the flow rate (gallons per minute).
Problem solving on the Barracuda
After staring at the shop manuals long enough, and reading
and asking around, I decided to go install a relay system. That seemed
much easier than rewiring behind the instrument panel. I already
had a big hole melted in my headlight switch connector, and wasn't impressed
with what the wiring diagrams indicated. A 14 gage wire carries most
of the current into the headlight switch, and a 16 gage carries it down
to the dimmer, where it drops to two 18 gage wires, one for high (red)
and one for low (black). The connection that had failed was
on the 14 gage input wire. That said to me that I would have to beef
up that wire as well as the ones coming out of the headlight switch, and
each and every connection would have to be gone over, including the ones
in the firewall connectors. The engine harness was replaced about
seven years ago with a nice repro from Year One. Its a good repro.
and every bit as inadequate as the original.
Once the electricity is done with the headlamps,
it has to return to ground. The original design is not so bad here.
Each headlight got its own ground wire (black with white stripe) that goes
to the radiator support and is held on with a sheet metal screw.
If there is paint underneath, or the screw doesn't tight anymore, or its
corroded, then the final connection will be bad. Also, realize that
the only connection back to the negative of the battery and the ground
of the alternator is through the engine block, and the only electrical
connection from the body to the engine is the little strap way over on
the firewall. Running another ground wire from the battery negative
to the radiator support can only help, and can be done very discretely.
Relays are remote switches. Send them power and
they turn a switch, Turn the power off, and they turn the switch off.
So, in a relay system, the high beam power is used to turn on the high
beam relay instead. Ditto with the low beam. A relay only draws
a drop of current so what was barely adequate becomes super overkill.
The real power is fed to the relays directly from the alternator (or battery)
using as heavy of a wire as required AND a circuit breaker or fuse.
It is almost always preferable to supply the power from the alternator rather than the battery. see Charging Circuit
The hardest items to find are good grade connectors
and relays. My sources were West Marine Discount, Waytek
Wire, and Radio Shack. Marine duty stuff is more moisture
resistant, the wire strands are all tinned, and sure it costs more.
I was going to use the automotive circuit breakers that reset themselves
(just like the ones in the Chrysler and AMC/Jeep headlight switches)
but instead went for the buss fuses in a sealed marine fuse holder.
Tough call for me.
Relays can be purchased in two patterns, 5 terminal
and 4 terminal. In both, two terminals are for the signal, in &
ground. In the 5 terminal, the two outputs can be arranged to be
both on and both off. That can simplify wiring. One can go
to the left light and the other to the right light. Or, one can be used
to feed your auxiliary lamps. That way, your fogs can only turn on
when the low beams are on, or your driving lights only when the high beams
But, be careful when buying 5 terminal, they also
come as double pole (DPST). In this arrangement, one output is on
when the signal is on, and when the signal is turned off, the other output
is on. Something is always on. Ooops.
I couldn't find a good replacement for the headlight
connector. The one NAPA carries was unimpressive, although its been
suggested since then that Autozone may carry a decent one. I disassembled
the harness, and used my original Chrysler harness as reference.
If you don't have two harnesses. then you will want to do some careful
measurements or trial fits of the wire lengths on the car.
1. Removed the headlight bezels and headlights.
2. The power for both headlights goes into the drivers
side headlight socket. The wires out to the left headlight is crimped
together with the power lead on to the connector. So the bundle
going to the connector has two reds wires (high beam in, left high beam
out), two black wires (low beam in, left low beam out) and black with white
stripe (right side ground). I decide to use the original wires to
signal my relays on the left fender. Since I wanted the socket, I
clipped the wire bundle, and reconnected the reds and the blacks by soldering.
The ends were then sealed with liquid electrical tape and cold shrink tape.
3. The left head light wire bundle was also clipped,
but only an inch from the connector. The leads were then ran to the
left fender. Connectors made for the relay sockets were then crimped
and soldered on.
4. Fun part. not. Slipping a cotter pin in the flat
T of the headlight connector, the catch was depressed and the metal clips
pulled out. This is when I found the crimps on the new harness weren't
that great. In fact the Chrysler crimps were observably better upon
close inspection. Then each metal connector was gently placed in
a wood jaw bench vise, and the crimps opened up. I used an ice pick
and small screw driver working in parallel to the wires from the insulation
crimp toward the front. It is possible the Packard 56 series 12 gage
connectors would work here. The 14 gage ones are too small, but otherwise
look and fit right. Made up a new high and new low beam wire out
of 14 gage wire connecting the relay connector to the head light
sockets. Instead of joining the wires in the headlight sockets,
I spliced them in line.
5. Made up two 12 gage wires with in line fuses
to carry power from the alternator "bat" stud to the relay connectors.
The connectors were only for 14-16 gage, but by soldering as well crimping,
I am sure I have very good connections. Same with the 18 gage signal
wires soldered to the same 14-16 gage connectors in step 3.
6. Made up a bracket for the relay connectors with
some sheet steel and some old rubber feet electronic cabinet(radio
or something) . Holes already in fender from former air conditioning
7. Made up new ground wires for each headlight,
a new ground to from the battery to the radiator support (12 gage marine
wire soldered to a very sad and corroded unused lead on the Belodon battery
cable, soon to be replaced). Made a second ground point on
the battery side of the radiator support just for the headlights using
a self tapping machine screw and nut left over from the speaker replacement
on the Grand Wagoneer. see, AMC still helping Plymouth ;)
'67 Barracuda Main Page
'85 Grand Wagoneer Main Page
Charging Circuit with Ammeter
Oct 13, 2001 rev May 2017