Hello all
I am installing a new head exhaust blower on my boat. The original unit is inaccessible. The hot (red) wire shares a feed with a dual switch controlling lights and blower power. I've pulled two new wires from the switch to the new blower location. In that I can't access the location of the original blower. I'm not able to find and use the common(blk) wire. Will any common wire I tap into work? Should I find the common bus in the panel and run my my new common to that location.
Thanks for any assistance.

 

Depends upon how much current the blower takes, and how big the common wire is that you find.

 

Amp draw is 4a at 12v, stepping down the existing 24v circuit to match blower spec. Which will increase amperage not a help if adding to arbitrary circuit common. Seem that it might best to find Common Bus in panel and either feed with new circuit wire or trace original blower common and splice, if possible.

 

Where is the step-down circuit located?

 

It is a module that I am putting in line prior to load.