hid custom wiring

I recently put a set of Bi-Xenon HIDs in my Sable. I'm going to have to do a bit of custom wiring to get both the low and high beams to work. There is only one bulb, but there is also a solenoid that moves the bulb backward in the socket, changing its angle in the lens, resulting in a "high beam".

Low: Power to Bulb
High: Power to Bulb and Solenoid

The 9007 socket supplying the power has three pins: Ground, Low, and High. Currently, I have "Low" wired to the bulb and "High" wired to the solenoid. Normally, the "Low" pin powers the bulb. When I flash the highs (pull on the stalk), both "Low" and "High" pins have power, so the bulb stays lit while the solenoid activates. Problem is, when I go to leave the highs on (push on the stalk), only "High" has power, so the solenoid activates but the bulb goes out.

I can't just bridge the two sides because the "Low" signal would always power the solenoid as well. As I understand it, I think I need a diode of some sort. I'm no electrical expert, so I was hoping someone might check my work and do a bit of math. I made a crude diagram of what I've come up with so far. Would that work? And if so, what type of diode should I get? The circuit is all 12v, but i'm not sure what I should be looking for as far as voltage/amperage ratings. Thanks for your help.

I assume this if for off-road use else is legal for road use.
If not, then DO NOT do it.


It's the green arrow.

Point the diode symbol arrow in the same direction - ie, you want current from the high to the low (but not the other way).

The line symbol on a actual diode aligns with the circuit symbol - ie at the end of the arrow head/tip; hence the line is towards the low HID.


As to size, it depends on the current. (eg if under 1A, then any IN400x diode; if under 3A, then any 1N580x or 1N582x diode - just ensure greater than 20V & 1A or 3A etc.)
But since you are powering the HID, and assuming each bulb is 35W - hence say 4A, allow 5A per HID or 10A for both.

There will be a diode voltage drop, but that shouldn't effect the HID since they are an SMPS - ie, (say) 8V or 10V to 16V is up-converted to the HID voltage.

I'd rather use an IN400x 1A diode to actuate a relay relay, but that would involve a slight break which probably isn't good for the HID. (Unless you add a big enough cap etc.)