FZ6 dual headlight, one low beam losing voltage when lighbulb is connected

[Bakasura]

Hey guys!
I have FZ6 from 2004 with dual headlight wich used to work fine and after replacing H7 lightbulb (wich burned out) it doesnt work anymore.
I have simply cut into H7 lightbulb 12v line and connected it to low beam connector on H4 bulb. So when bike starts they both light up.
Low beam on H4 is shorting to ground as soon i put lightbulb into the connector. When lightbulb is out i have 12v going to LB connector.
To clear it out:

H4 lighbulb is out of the connector, H7 lighbulb is connected to its connector

1. H7 low beam works fine
2. H4 low beam has 12v on the connector
3. Voltage between H4 and H7 low beam connector is 0v (wich is ok considering they have same source of 12v)
4. H4 high beam gets 12v on the connector when its turned on on the switch

H4 lightbulb is connected to the connector, H7 lighbulb is connected to its connector

1. H7 low beam works fine
2. H4 low beam gets shorted to GND
3. Voltage between H4 and H7 low beam connector is 12v (meaing H4 is shorted)
4. H4 high beam gets 12v and works just fine when its turned on on the swich

I have tried new H4 lighbulb - same thing
I have tried both H4 lighbulbs out of the motorcycle and both high and low beams work on both lightbulbs.

One odd thing to me now is that when i measure voltage on the connectors between H4 and H7 12v line (while lighbulb is connected) i get 12v meaning H4 low beam really is shorted to GND but at the same time it is physicaly connected to 12v line that is goes to H7 lighbulb.
There is no rust on H4 connections or anything that could prevent or short pysicaly Low beam with GND.
And to suspect there is something wrong with GND on H4, but then again i ask myself how does High beam work fine when i turn it on.
I dont know what to think anymore and what to look for. This doesnt make sense to me but it is how i discribed it.
Im open for any suggestion.

Thank you for your help

 

[Motogiro]

H4 lightbulb is connected to the connector, H7 lightbulb is connected to its connector

1. H7 low beam works fine
2. H4 low beam gets shorted to GND
3. Voltage between H4 and H7 low beam connector is 12v (meaning H4 is shorted)
4. H4 high beam gets 12v and works just fine when its turned on on the switch

If #2 were true, and shorted to ground, current would go high and the fuse for that circuit would blow.

This logic points to there being high resistance in your jumper connection.
Naturally using your high beam without turning off low beam overheats the H4 because the high beam filament is designed to be switched off to prevent overheating.
I would carefully examine your added wire and plug connector because there could be damage and high resistance. If there is a dead short there would be a blown fuse.

 

[Bakasura]

If #2 were true, and shorted to ground, current would go high and the fuse for that circuit would blow.

You were right about this one. Didnt think of it at first.
I want to thank you for your help. It was loose connection. That wire i added somehow had loose connection after i checked it. Now its secured and everything works fine as it used to. Thank you.

And as for H4 filaments i plan to make low beam turn off when high beam is on, using relays.