12v going away

[laserfish]

Putting in a new bilge blower and having problems. I can hook the motor directly to the battery and it works great. I can meter the switched wires and get 12.5v with the switch on. Hook the wires to the blower and the voltage goes to zero. Help, what can be causing the voltage to go away and where is it going.

 

[dubs283]

Either bad lead or bad ground

Look at possible ground buss for issue

 

[mike_i]

When you connect the wires to the blower where are your meter leads at when measuring 0V? With the blower connected connect the pos lead to the pos side of the blower and connect the neg lead to the neg terminal of the battery or to a known good ground and report back with the results.