Newell Gurus

Getting closer on the engine swap, now I have some electrical questions Mike is asking me and I need help to answer him.

The Cummins ECM, ZF transmission ECM and shift pad are all 24v. On the shift pad, a 10a 12v - 24v step up converter will work, but I'm pretty sure the ECMs will be drawing more amperage than a $15 step up converter is able to handle.

Right now, the coach has two 12v starter batteries, I was wondering if I could wire them where I could have 24v in the engine bay for the ECMs and keep my 24v alternator and 24v starter?

Any help would be appreciated!

Prevost conversions almost always run dual 24 volt and 12 volt systems. They use a Vanner Voltmaster battery equalizer. You do have to be careful in a retrofit to make sure the 12 volt and 24 volt systems are isolated from each other and marked so that you don't inadvertently wire 12 volt systems into a 24 volt line.

Wiring the chassis batteries in series you will get the 24 volts you need. You could add a 12 volt alternator to charge the existing house batteries which are wired in parallel. You would have to disconnect the solenoid that allows you to merge the battery banks since they would be at different voltages now. The devil is in the details but it is doable.

Thank you Michael, the donor bus has a unit that separates the 12v and 24v systems that we may be able to use. What I'll have to figure out is how to get the 24v batteries charged off the generator and shore power. I have an engineer friend stopping by for drinks tomorrow, he'll possibly have some ideas. He's helping me figure out a digital dash running off an Android tablet.