Hodgson Concrete

I had no reverse lights or alarm on a 2005 DM 690S, checked power & had no power. Checked power into & out of switch, power is good. Ran a new wire from switch to reverse alarm, alarm started working, plugged light it & tripped a relay. Relay reset three times then stopped resetting & I have no diagram telling me what relay is for what. I swapped all relays that I could find, have power but as soon as I connect light or alarm, power gets real weak, disconnect & power comes back. Any ideas would be greatly appreciated.