Off Camera Flash Question

When taking portraits, I have a 580EX II mounted on my 30d and use it to also wirelessly trigger another 580 EXII to my right. I also have a 430 EX behind the subject that fires upward to the background. However, because it is behind the person, the 430 EX doesn't always trigger due to the fact it is not in the line of sight.

My question is this: Is there a way I can hook up a wire either from the flash on my camera or the camera itself to the 430 EX so that it triggers every time? Or is there a better solution?

Thanks for you help!!!

If you want to trigger the 430 EX with better reliability, as far as I know, ETTL will be lost if you, e.g., use optical slave or pc cord. Radio transmitters do not give you ETTL either, except the recent new products.

Other people have just talked about something similar: https://photography-on-the.net/forum/showthre​ad.php?t=747146

pc cord. or instead ofusing IR to trigger, get a transmitter/receiver that uses radio channels.

This is indoors I assume?

Have you rotated the flash head on the 430ex 180 deg. so that the IR window points towards the camera?

Also, where does your flash on camera point to? I usually aim it at the ceiling indoors since the reflections seem to reach every flash a bit better doing that sometimes.

Yes this is indoors. I try to point the IR's towards each other but the flash behind the subject doesn't always trigger. Could I use some kind of sync cord (from Flash Zebra) from the 580 EX II on the camera to the 430 EX behind the subject, while at the same time utilizing the wireless functions to trigger the second 580 EX II? Or will the sync cord stop all wireless functions?