decolliber

I am going to install a pair of Lightforce 140s on a 2004 Forester (automatic, non-turbo). I know that if I activate auxiliary light relays from the high beam power circuit (the red power wire to the headlights) that the auxiliary lights will also come on with the DRLs. Is there an accessible circuit that I can use to activate the relays without the aux lights coming on with the DRLs? I would prefer not to disable the DRLs.
Looking at the headlight wiring chart, it appears that if I activate the relay from any of the terminals on the high beam relay, that the aux lights will still come on with the DRLs.
The high beam indicator light circuit looks promising, assuming that the high beam indicator does not come on with the DRLs.

Attached Files

Headlight System.pdf (60.4 KB, 80 views)

bbottomley

Darned if I wasn't working right now on a DIY writeup about just this very thing!

You can drive your relay from only the high beam if you connect it across the common plus terminal and the high beam switched ground terminal on either of your headlights. Try the links at the bottom of this post. And here's a link to the pinout on the H4 bulbs that your Forester probably uses.

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decolliber

Thanks for the quick reply!

I wired my previous set of auxiliary driving lights with one side of the relay coil going to the red high beam wire and the other to ground. Since they then stayed on when the DRLs were on I assumed that the DRLs must be high beam. Now I see the wiring diagram shows the DRLs operating the low beam headlights, but the DRL control module is also connected to the coil of the high beam relay (???).

One thing puzzles me. Does low side switching mean that the headlight power source (M/B fuses #8 & 9) are always live when the ignition is on, since the relays are downstream toward the ground? If so, why would aux lights, with relay wired to red high beam wire and to ground, not be on whenever ignition is on? Perhaps there is another switch not shown in the wiring diagram I attached above.

decolliber

And one more question. Would there be any problem with connecting the coil circuit on an aux light relay switch to the coil circuit on the high beam relay (GB2 and GR3 on the attached diagram)?