DS-50 issues

I recenly got an Ikelite 5D housing and two DS-50's...one of them is too old to use with ttl or even pay for the conversion so it'll probably go at some point but all I have for now... I just got it(was an idiot and didn't look at the serial) and am playing around a little bit. Testing things with my 20D in the housing for the moment, hopefully have a 5D body within the next month or so when they start to drop in price.

I set the circuit on the housing to manual mode as well as the strobes...no matter what power setting I tell it though pictures look like they're lit about the same. Would think they'd come out lighter or darker depending on how I set the power? Also I'm getting some random fireings.

Older strobe is on the 'red' cable, newer ttl strobe is on the unbanded cable. Blue is connected to the housing. Also as an alternate option, am I better off using a single strobe cord on the newer strobe with ttl turned on and a slave sensor on the second strobe?

Thanks

Matt

Few ideas:

not sure how the older and newer mix works out. DS-50 has only Full and 1/2 power settings. The manual power settings on the housing still use the TTL control. To be completely manual, both strobes and housing have to be set so, but you should be able to see the 1/2 setting.

Random fireings are scary, and might mean that there is some faulty wiring.

Also: do the 5D and 20D have exactly the same TTL protocol ?