Set up DRL with high beam?

[wjbell]

Where would I start if trying to have my high beams come on as daytime running lights? I'd like just the high beams (no parking lights) to come on with the key. The other thing is, I'd like them to come on at 30-50% power. Then if the regular headlights are turned on at the switch they could stay on or go off. (I'm sure going off would be a harder setup) And when the high beams are toggled they act normally.

It seams like this would be a fairly simple wiring connection to the already ignition switched headlight switch in the cabin, with maybe somthing inline to reduce the power.

Is anyone familiar with this?

[Espen]

hmm may I ask why you would like a setup like that?

I have wired up a DRL in my 525 myself, after Javier instructions that is. But mine is a regular, with only headlights turning on when engine is running.

[SharkmanBMW]

To get an e34 past Canadian inspection while importing, you would have to add DRL... (but that is NOT the same as what you want) so it could be as simple as a relay being addes to your system... ask Javier for the details.

If it must be your way with the high beams, I dunno!

[SC David]

I'm interested to see the result of this. Sounds like what they have going on euro E36's, and some of the early E39's here. It should be pretty cool if you get it working right.

[Javier]

the 30-50% power. Standard BMW high beam lamps are 55W, two of them mean 110 W, that represent a total operating load of 1.3 ohm. "Something in line to reduce the power" would be a .7 ohm power resistor (I would use a D50K1R0-ND), that would reduce lamp power to about 42%. But the heat dissipated by that resistor would correspond to about 25 wats. Pretty hot, not to be installed in the dashboard, but near the radiator fan. A chopping electronic circuit may be more efficient, also more complicated to put together if you don't know how to. Don't know either its effect in the lamp life.

To set together your project in case you desire this heat generator under your hood, you will need the resistor and two relays (one of them need to be 5 pin), this is the connecting table (draw it so you can see what is going on):

-Relay #1 coil + (86) wired to Relay #2 contact NC (87a)
-Relay #2 contact com. (30) wired to Fuse F2 output (power in run and start)
-Relay #1 coil - (85) wired to ground
-Relay #2 coil + (86) wired to Light switch pin 3 (Tap Yellow wire in socket, it is Low beam on signal to turn off DRL, if you want turn off for park & lows, use light switch pin 4 by taping Yellow/Violet wire in socket)
-Relay #2 coil - (85) wired to ground
-Relay #1 contact com. (30) wired to LKM pin 2 (Tap red wire in socket, it is permanent power)
-Relay #1 contact NO (87) wired to resistor pin one
-Resistor center pin wired to fuse F13 input (Tap White/Red wire in socket, it is High beams feed)

Set resistor to about 0.7 ohm, re adjust slightly for lights brilliance required.

Relay #1 is DRL (turn on reduced power High Beams with ignition key)
Relay #2 is DRL off when Low Beams (Or Lows & Park if selected)

Javier

[wjbell]

Ok, I think I can follow that but just a couple questions..

Where can I buy the resistor and the two relays? Is there a part number for the two different relays? Are they standard electronic parts or somthing from the BMW dealer?

Also you say, "Set resistor to about 0.7 ohm, re adjust slightly for lights brilliance required."

Is this an adjustible resistor, how do you set it?

Also, What guage wire should I be running to the resistor?

Thanks for your help.

the 30-50% power. Standard BMW high beam lamps are 55W, two of them mean 110 W, that represent a total operating load of 1.3 ohm. "Something in line to reduce the power" would be a .7 ohm power resistor (I would use a D50K1R0-ND), that would reduce lamp power to about 42%. But the heat dissipated by that resistor would correspond to about 25 wats. Pretty hot, not to be installed in the dashboard, but near the radiator fan. A chopping electronic circuit may be more efficient, also more complicated to put together if you don't know how to. Don't know either its effect in the lamp life.

To set together your project in case you desire this heat generator under your hood, you will need the resistor and two relays (one of them need to be 5 pin), this is the connecting table (draw it so you can see what is going on):

-Relay #1 coil + (86) wired to Relay #2 contact NC (87a)
-Relay #2 contact com. (30) wired to Fuse F2 output (power in run and start)
-Relay #1 coil - (85) wired to ground
-Relay #2 coil + (86) wired to Light switch pin 3 (Tap Yellow wire in socket, it is Low beam on signal to turn off DRL, if you want turn off for park & lows, use light switch pin 4 by taping Yellow/Violet wire in socket)
-Relay #2 coil - (85) wired to ground
-Relay #1 contact com. (30) wired to LKM pin 2 (Tap red wire in socket, it is permanent power)
-Relay #1 contact NO (87) wired to resistor pin one
-Resistor center pin wired to fuse F13 input (Tap White/Red wire in socket, it is High beams feed)

Set resistor to about 0.7 ohm, re adjust slightly for lights brilliance required.

Relay #1 is DRL (turn on reduced power High Beams with ignition key)
Relay #2 is DRL off when Low Beams (Or Lows & Park if selected)

Javier

[Javier]

will guide you to the Digikey web page corresponding to the model I'm suggesting (D50K1R0-ND), it is an adjustable resistor. The relays may be standard BMW relays. Relay #1 is identical to fuel pump relay K201 (A single NO contact). Relay #2 is identical to Unloader Relay K3 (a single double trough contact).

I'm sure you can get cheap relays similar to BMW's.

For wiring the resistor, I would use similar wire gauge than the one arriving to LKM Pin 2. In general a 105 degrees machine cable AWG #14 should do.

Javier

[Javier]

tap the LKM pin 2 wire with an in-line 10A fuse. The circuit trough the LKM to the fuse box is short and reliable. That will not be the case for running wires around, to and from the resistor, so better protect it.

Javier

[wjbell]

Thanks Javier. When I get the parts I'll try it out and post a little writeup about it. My main concern is getting to the fuse and LKM wires, doesn't look like it's going to be an easy task. Do I have to pull that whole LKM fuse box out?

[Javier]

drill a Small hole at the LKM box and catch the LKM pins at the LKM PC board connection pins (soldering to them). Then run the wires out trough the hole and implement a separable connection so you can remove the LKM and detach the wires.

Here is a view of the LKM connector pin, note it is the socket view.



Javier

Edit: THe fuse F2 output can be catched at Light switch pin 10, Green/Blue wire; fuse F13 input can be catched at LKM pin 20.