Chaos among my four electrical circuits

[Smokey]

I have a 1995 Suzuki DT 40 TC. In addition to the electrical circuit that serves the motor/tilt/throttle-shift box/dashboard gauge, I have three additional circuits attached to my battery (a Walmart Everstart 24DC which has specifications to easily ac comodate all four circuits): (1) lights (bow/stern/compass), (2) sonar (depthfinder/transducer), and (3) radio-telephone (receiver/antennae).

The old radio-telephone needed to be replaced, so I bought a new one (Cobra) and attached it -- correctly -- to the same wires that the old one had used. Chaos now ensues. Can someone figure out what has happened? Following is a chart of what works and doesn't work at this time:


Status of Circuits Both With and Without Motor (M) Also Attached to the Battery:


Without Motor Attached: Lights (L) - OK; Sonar (S) - OK; Radio (R) - OK; L+S - OK; S+R - S functional, R not; L+R - OK; L+S+R - L & S functional, R not

With Motor Attached: L+M - L functional, M not; S+M - OK; R+M - OK; L+S+M - OK; S+R+M - OK; L+R+M - L & R functional, M not; L+S+R+M - L, S, & R functional, M not

[artdf175]

At first this had the feeling of a high school algebra problem!
One of the circuits has the polarity reversed
How does the radio with DSC interconnect with the chart plotter?
Are you using a NEMA 2000 system to interconnect the various?
Art

[Smokey]

Problem Solved; Stupidity Confirmed

I finally figured out what the problem was -- a battery which NOMINALLY had enough power to handle all of the four circuits actually did not have enough power. New better battery equals all circuits functioning in any combination. The sarcastic moral of the story is to never try the simplest action first.