after fixing battery connection problem on my 1994 bmw 325ic when car is started on 1994 BMW 325i

fuel gauge shows empty and temp shows hot

Asked by for the 1994 BMW 325i
did you short battery cable when installing new battery?
I didn't actually change battery.Battery appeared to be dead but when I checked I found that the negative cable was loose so I just tightened it.Then when I started the car is when the gauges malfunctioned.
thats the same thing you lost pwr