Chassis Electrical System
This is the 24-volt system that came with the bus from the Neoplan factory, and supports all the exterior lighting and other over-the-road systems that any motor vehicle needs to have. The original alternator and starter, and likely the batteries as well, were swapped out as part of the Detroit 8V92TA installation. Odyssey now has a Delco 50DN 270-amp oil-cooled alternator, and two flooded-type size 8D batteries for starting the main engine and running the chassis systems. 270 amps (around 6.5 kilowatts) is a lot of power, and the available capacity of this alternator was among the factors that persuaded us to stay with a 24-volt system for the house system as well.
A small handful of chassis electrical items (for example, the ATEC computer) require 12 volts, and for this purpose there is a center tap from the batteries, as well as a Vanner 50-amp battery equalizer. (The Vanner was already in the coach when we bought it.)
I won't go into any great detail about the chassis systems, as they are mostly stock. We did go through the entire exterior lighting system and replaced all the original incandescent fixtures with LEDs. We were able to get 24-volt LED units for most of the lights, although we had to glass-over and re-cut most of the mounting holes for the large ones. On some of the side marker locations, we could not get 24-volt models that were suitable. In those locations, we simply doubled up on 12-volt items and wired them in series. The coach already had high-mounted stop/tail lamps on the rear cap, and when we re-did these, we also added high-mounted turn signals, making Odyssey, and her intentions, quite visible from the rear:
The other modification we made to the chassis system was to install Intellitec remotely operated battery disconnects on both the 24-volt and 12-volt outputs from the batteries, with a switch in the cockpit. If we need to park the coach for any length of time, we can shut off the chassis batteries so they are sure to be good-to-go when we need them. The Intellitec units are basically 100-amp latching solenoids with 12-volt coils. We've wired the coils in parallel, so one switch turns on or off both the 24-v and 12-v outputs. (The alternator, starter, and Vanner are wired behind the disconnects, so the solenoids don't every carry those high-current circuits.) Here's a diagram, which includes the house system.
A Xantrex PathMaker unit allows the chassis system to feed the house system so that the excess power from the 270-amp Delco can be used to charge the house batteries while under way. A driver pushbutton can force the PathMaker to connect, making it into an "emergency start" relay that allows us to "jump" the chassis batteries from the house system. The PathMaker normally connects the two systems together when either system's voltage is at a charging level. We've defeated this on the house side, so the unit only connects when charging voltage is present on the chassis side. This is to keep the flooded cells of the chassis system, which have start battery profiles, from messing up the charge rate of the house batteries when charging from the house charger.