E-Code wiring question

[Jamie]

I've studied the diagrams and have read a few installation stories, but
I am not quite clear on one issue.

Am I correct to plan to wire the e-codes as follows?

1) [Fact] A wiring harness extends from the firewall to the headlights
on both sides, there are two harnesses - one harness per side.
A) [Fact] I plan on wiring from my battery, it is on the
passenger side. Therefore, this will be the side with the relays.

B) On the driver's side, I will use the existing wiring for the
turn signal and running light and NOT use the wiring for the high/low
beams. These wires will be terminated (not connected to anything).

C) On the passenger side, I will use the existing wiring for the
turn signal and running light. I will use the headlight wiring to
connect to the relay/wiring kit. The low beam wire will go through a
fuse to the low beam relay and the high beam wiring will go through a
fuse to the high beam relay. From there I will connect the respective
wires to the headlight on the passenger side and jumper the wires and
extend the wiring across the front of the car to the driver's side to
connect over there.


Does this sound right? The two main questions are: do you only use one
side's harness for both sides' headlights? Second, if so, are there
separate wires on each side, 1 for high, 1 for low and 1 common?

Thanks!

 

[Jamie]

Sorry, follow up question:
Does my 1987 Volvo 740 have a "ground-switched" headlamp circuit? I
noticed a ground wire on each side coming from the harness. This
grounds to a bracket mounted on the quarter panel - 1 per side.

Must I follow Dan Stern's instructions for this type grounding, or does
it not apply?
He states:
"SPECIAL CONSIDERATIONS FOR GROUND-SWITCHED SYSTEMS

Many Japanese vehicles, as well as a few others, use a
"ground-switched" headlamp circuit. In these circuits, the headlamp and
beam selector switch break or complete the ground side of the headlamp
circuit, rather than the feed side. On these systems, it's imperative
to use both negative and positive existing headlamp wires to trigger
the relays. It is tempting to run the existing headlamp feed wire to
relay terminal 86 (trigger feed) and simply find a convenient ground
for relay terminal 85 (trigger ground). However, this will not work
with ground-switched systems. Run the vehicle's existing feed wire to
terminal 86, and run the vehicle's existing ground wire to terminal85.

Now, what are we going to do now that we've used-up our one and only
ground wire on the 85 terminal of the low beam relay, but we still have
to install the high beam relay? Go to the other side of the car and you
have another ground wire! Remember, the relay trigger circuits can be
as long as you like, because they take insignificant power. So, you can
extend the vehicle's existing headlamp wires to your relay mounting
location. It is fine to use this method regardless of whether you have
a ground-switched system or not, so go ahead and use it if you're not
sure. "

http://danielsternlighting.com/tech/relays/relays.html

 

[James Sweet]

I've studied the diagrams and have read a few installation stories, but
I am not quite clear on one issue.

Am I correct to plan to wire the e-codes as follows?

1) [Fact] A wiring harness extends from the firewall to the headlights
on both sides, there are two harnesses - one harness per side.
A) [Fact] I plan on wiring from my battery, it is on the
passenger side. Therefore, this will be the side with the relays.

B) On the driver's side, I will use the existing wiring for the
turn signal and running light and NOT use the wiring for the high/low
beams. These wires will be terminated (not connected to anything).

C) On the passenger side, I will use the existing wiring for the
turn signal and running light. I will use the headlight wiring to
connect to the relay/wiring kit. The low beam wire will go through a
fuse to the low beam relay and the high beam wiring will go through a
fuse to the high beam relay. From there I will connect the respective
wires to the headlight on the passenger side and jumper the wires and
extend the wiring across the front of the car to the driver's side to
connect over there.


Does this sound right? The two main questions are: do you only use one
side's harness for both sides' headlights? Second, if so, are there
separate wires on each side, 1 for high, 1 for low and 1 common?

You'll want to bridge the harnesses between the two sides, you can do
this easily enough with some of those insulation piercing connectors
under the fuse box right at the bulb failure sensor or you can run wires
across under the hood, this will prevent the headlights from tripping
that but retain functionality where you really need the failure warning,
for the taillights.

Yes there's wires on each side just as you describe.

You don't need to fuse the headlight wires to the relays, they're
already fused at the fuse box (I think?) actually it never hurts to have
another fuse. *DO* fuse the wires straight off the battery before the
relays though. I got some nice waterproof inline fuse holders at Schucks
when I did mine.

 

[Jamie]

Thanks james. I wasn't sure about that headlight failure light.
Bridging sounds like a great idea. How did you ground yours? I see a
grounding bracket on each side with 1 if not 2 wires being grounded.

 

[James Sweet]

Thanks james. I wasn't sure about that headlight failure light.
Bridging sounds like a great idea. How did you ground yours? I see a
grounding bracket on each side with 1 if not 2 wires being grounded.

I bridged mine under the hood, I mounted the relays back next to the
power steering fluid resivoir and ran wires enclosed in flex tube. If I
were to do it again, I'd bridge the sides at the lamp failure sensor.