Install Sunyee Cree 126W light bar - SG II Forester

It should be possible to pick up the high beam relay switching terminal in the fuse box in the engine bay, and jumper this to the switching terminal on the light bar, via the cabin switch.

IOW, switch the light bar relay using the high beam relay switching circuit, rather than the high beam current carrying circuit.

I will try this tomorrow ...
 
The relay connection didn't work.

However, I have managed to achieve something tonight.

By wiring the red wire from the cabin switch to the black wire from the headlight and the black wire from the cabin switch directly to the battery negative, the light bar now comes on only with the low beam, and switches off on all other settings.

If this is attainable, the opposite should also be attainable, where the light bar only comes on with the high beam and switches off on all other settings.

More experimenting tomorrow. It's too cold and dark ATM ...
 
Guess what I have just found ... :poke:

Under the inner/bottom of each headlight is a grey plug. This plug has six wires entering it from the car wiring loom.

BE WARNED: These are both right next to the front air bag/SRS sensors (CODED YELLOW). BE VERY CAREFUL not to disturb either of these ...

I have not tested the voltages, but I suspect at this stage that three of these are the power feeds for the parking/low beam/ high beam lights, and another one is the common earth. There are two other black wires, one light gauge and one heavy gauge. There is one white wire.

The D/S one has some different colour coded wires.

Methinks I will have a coffee, then attack these with a multimeter ...
 
Checked out how i actually wired mine in this arvo, I must of felt lazy that day as I just wired the energizer for the relay in parallel to the high on the h4 globe. I think i must of done this as both the hi and low share a common load wire.
 
That's about the only thing I haven't tried yet ...

Like PauSum, I have found that by reversing the polarity of everything to do with the light bar and connecting it 'backwards', I can get it to not come on with the low beam.

However, also like PS, I found that it comes on with everything else - high beam, parking lights, no lights, no key in the ignition ...

I am damned if I can work out how Subaru have switched the high and low beam separately!! I disconnected everything behind the dash (with the exception of the SRS system), and everything still worked! Lights (front/rear), indicators.

What cretin thought up this switching system?

If it were an active wire switched system, I could draw the circuit diagram for it while half asleep, and wire it just as easily, regardless of whether positive or negative ground.

I have now wasted nearly 2 days on this, and no further along! :madred: :yell: :furious: :puke:
 
RB, why don't you save yourself a LOT of time and hassle & just follow the diagram I posted. I've told you it works, and its simple and easy :poke:
 
Gidday NL

There is one flaw in that suggestion, mate - It doesn't work ...

The series II SG has (very) different wiring.

I have just now solved how to make it work.

The relay main earth (heavy black lead) and the relay trigger wire (light gauge red wire) need to be connected to the two high beam wires.

[Edit] The heavy red wire from the light bar relay is connected to the postive battery terminal. [end edit]

The light bar relay switching earth wire (light gauge black wire) is not used.

Put these two wires onto the high beam wires (B -> B and R -> R) via two vampire connectors onto the high beam light leads.

The light bar will now switch on only with high beam, and is off at all other times.

To avoid overloading the high beam circuit, it would seem to me to be a good idea to have a secondary dumb slave relay between the light bar main earth wire and the battery. That is, the new relay is connected via the vampire connector, and switches the main light bar relay earth to the battery.

This relay should be able to be wired conventionally, but only one side of the load (earth) needs to be connected (or should be??). Probably best to leave the other side disconnected.

I will have to dig out some relays I have in the garage and finesse this side of the arrangement.

Each side headlight assembly is on a separate 15A fuse in the series II SG. The headlights are 60W (HB) plus 55W (LB) and the parking light is 5W. Total 120W = 10A. The light bar draws 126W (but apparently draws less than this in terms of amperage - about 8.5A, IIRC), but is also partly connected via the heavy gauge lead to the positive terminal of the battery, so hard to do a straight sum to work out what the amperage on the relay ground connector is adding to the overall amperage being drawn on the circuit. The multimeter I have can measure up to a 10A current in both AC and DC, so it can be measured but not without disconnecting the vampire lead.

What a Heath Robinson method of connecting this!! I am still amazed that it works at all ... :rolleyes: :shake: :shrug:.
 
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How are you using the switch if you connect the relay between the +ve & -ve high beam wires?

Its simple...
Ignition to switch red (+ve)
switch black (+ve) to relay 86
relay 85 to high beam (-ve)
relay 30 to fuse to battery
relay 87 to lightbar (+ve)
lightbar (-ve) to chassis

It doesnt matter if the wires arent the same, the concept is. It really is easy...the only hard bit is that you are complicating things with using a OEM switch with a tangle of wires. It really only needs 3 wires... power in, power out & earth for the globe
 
^ For this entire process, I have used the switch that came with the light bar.

The OEM switch that I have has additional wires for switch illumination (panel lights) and operation (lights when circuit in use, i.e. light bar is switched on), just like the standard fog light switch. I worked out which of these wires areused, and how they are connected. The purple wire needs to be jumpered to the fog light terminal to connect the panel light into that circuit.

The supplied switch uses a three pin connector into the light bar main wiring loom. It is being used exactly as manufactured and supplied.

The problem lies in the crazy way Subaru switches using the (negative) ground circuit, and then jumpers various wires at the device being switched!

It is this design flaw that requires what amounts to a double pole switch arrangement for the light bar to work.

The headlight relays in the main fuse/relay box does not have a 'local' switching wire. I have been unable to identify this switch wire at any exposed part of the wiring loom ...

Searching the internet uncovers quite a few other brands of vehicle that also have this problem ...
 
This exactly, ...ish, I like my lazy way, Physically cut into the loom at the headlight. Run closed within the hibeam globes circuit. positive or negative switched, if this doesn;'t work your car doesnt obey the laws of physics.

Its simple...
Ignition to switch red (+ve)
switch black (+ve) to relay 86
relay 85 to high beam (-ve)
relay 30 to fuse to battery
relay 87 to lightbar (+ve)
lightbar (-ve) to chassis
Click to expand...
Bat + positive -----30ampfuse----30 on relay-> 87 relay---(+)Lightbar(-)------Chassis (-) earth.

@ P/S headlight Hi/low common (+)-----85 Relay -> 87 relay-----(Cabin switch)---------(hi-beam (-) @ globe)

additional load to P/s hi-beam circuit > 160milliamps. If you measure more than this your relay is a crappy chinese one which will probably catch on fireburn your house down and sell your friends sisters cousin's, horse to a glue factory.
 
Gidday Id

On the connector I discovered earlier today, there are two wires that are obviously some kind of control system for the H/L beam circuits. They each show around 75~100 Ohms resistance to earth (negative terminal on battery). It appears to me that it is the existence of this 'hidden' controller that prevents any straightforward approach to this problem from working, i.e. using any kind of single pole solution, as I have used for nearly 50 years.

What I have done works. It uses a double pole switching approach.
 
Subaru headlight wiring just seems labyrinthine for absolutely no reason what so ever, as i think Dedman found out just trying to remove voltage drop in the factory loom.
 
Just because I really like the marque doesn't mean that I am blind to the little design faults here and there!

Like the OEM headlight connectors in my Impreza. Non-thermoset plastic! Bloody things melted when the Narva bulbs dropped one filament across the other. I cut them off and replaced them with thermoset plastic ones.
 
Pressure's on

Don't want to have 2 light bars sitting in the garage doing nothing :cry:
will try to look into this on the weekend when I have the car.
Thanks everyone for the inputs
 
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I forgot. I haven't crimped on the earth wire vampire connector yet.

I can measure the current draw tomorrow morning.

If it's less than a couple of amps, there will be no need for a 'slave' relay.

Sure throws out a bucket load of photons ...
 
Ah, the joys of negative switching :rotfl:

Its the reason I first googled it when I was attempting to rewire my headlights loom and came upon these great Subaru forums. The rest, as they say, is history :biggrin:
 
^ It's not just the negative switching, it's the convoluted way Subaru have gone about it.

The multimeter shows that there is some kind of remote controller circuit board that has wires present at the headlight connection - the six pole grey headlight connector under the inner/bottom of the headlight assemble. Two of them, in fact. These must control the relays remotely, making the relay switching system impossible to find (for me, at least - not that that would be too hard to do ... ;) ).

Using a double pole wiring system for the light bar appears to overcome this problem. I will measure the amperage drain off the negative HB wire tomorrow.

Once I have finalised this, I will modify and re-post my previous wiring diagram so that it shows what I have done.

Interestingly, the 30 y.o. Hella 30A relay I found in the garage has the same numbering as the modern Narva relay you posted before, NL. Unless someone can identify the HB relay switching wire somewhere in the series II SG, it is useless too as a single relay solution.

Absolutely knackered now ...
 
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