high + low at same time with hid harness?

Just got a bi-xenon HID harness to use with a single HID kit. The HIDs are installed in an aftermarket projector capsule which uses a separate bulb for the highs and lows connected through a single harness. The HIDs are being used for the lows and I am going to keep halogen in the highs since I never really use them. The reason for getting the bi harness was to be able to keep the lows on when the highs are used. I don't use my highs much, but just in case I have to or hit the switch by accident, I don't want the HID ballast to repeatedly turn off and on. I got it installed, but found out that the harness does not allow the lows to remain on when the highs are turned on. I will only be powering the lows through the HID harness, the highs will be powered through the stock harness. The harness is a bi-xenon hid harness. It has battery and ground, a 9007 male plug to get the signal from the stock wiring, three relays (two SPST and one SPDT - I think), and four connectors for the HID ballasts (two for each side). When I turn the lights on, the lows through the harness work for the low side and when switched to high, only the highs work. What would I need to change on this harness so that the lows remain powered whether the switch is on low or high. Thanks!!!

So just stick the diode between the low and high + on each side? Any other way to do this? I don't want to start cutting up this harness if I don't have to.

Would adding a jumper wire from the high + in the stock harness to the low + in the HID harness work?

A jumper would make both lights come on any time one of the lights were on.

I found another way using the stock wiring. Bridge a wire from the DRL diode to the headlamp switch. Don't understand why this works, but apparently it does. I'm going to try this first and if that doesn't work, I'll try your method. Thank you for the replies!