Help required with 24v to 12v reducer install (1 Viewer)

[CruisinKempy]

HI all.
I've done enough reading to have a fairly good understanding of how I can rig up a 24volt to 12 volt reducer in my 1990 70 series 1 PZ system... though through all my searching I can't solve one final dilemma.

My reducer has 1 each of 24+ and 24- wires. I plan to ground the negative to common ground and run a fused 24+ connection from the battery to the reducer 24+ wire. But when it comes to the 12 volt side I'm still a little unsure. It also has 1 each of 12+ and 12- wires. The 12+ will run to a fuse block. However, do I ground the 12- to the common ground as well or do I have to run that to my powered items?

The question really is... SHOULD both of the negative (24 and 12 volt) wires be run to common ground or does the 12 volt side need to be a complete non grounded loop back into the reducer unit for it to operate correctly.

Thoughts and ideas appreciated. My initial plan was to ground the 12- wire from the redcer to common ground but I would like a second opinion.

Cheers.

 

[Freewheel]

I kept mine separate, and have fused terminal blocks for the + side and a non fused terminal block for the negative. Not sure if it's strictly necessary, but I'm an Audio engineer, and have respect for the negative effects of ground loops (multiple paths to ground) in audio systems, so I decided to keep the whole 12v install cleanly isolated from the 24 volt systems chassis ground- especially since the main reason for the 12 volt converter was for a stereo system and a VHF radio. It's worked perfectly for 10 years, so I can say that it's been successful, but it does require a bit of extra wiring.

 

[CruisinKempy]

I kept mine separate, and have fused terminal blocks for the + side and a non fused terminal block for the negative. Not sure if it's strictly necessary, but I'm an Audio engineer, and have respect for the negative effects of ground loops (multiple paths to ground) in audio systems, so I decided to keep the whole 12v install cleanly isolated from the 24 volt systems chassis ground- especially since the main reason for the 12 volt converter was for a stereo system and a VHF radio. It's worked perfectly for 10 years, so I can say that it's been successful, but it does require a bit of extra wiring.

That sounds like a good option! So if I read that correctly... the -12 from the reducer will be the main connection out of the non fused terminal block and all negative lines from the accessories will run into that non fused terminal blocks ports... thus creating a complete loop from the reducer 12+ out to the accessories (via a fuse block) and back into the reducer via the -12 wire. The 12 volt side of the reducer will not ground to the vehicle itself, but the 24volt system will be business as usual and can be grounded to the common ground.

I like the idea, as long as I have got the right end of the stick it seems to me like an option I would be keen to run with.

 

[In2cruisers]

I went the easy way....bought 2, now running one constant and one switched

 

[Freewheel]

Yep, sounds like we're talking about the same thing.