Bus Wiring and House Batteries

[mung]

I am going to be converting my 4104 to negative ground and fixing all of the chafed wires.  During this operation it seems like now would also be the time to try to separate the items needed for starting and running the bus from those used for house systems like an RV would have.  Has anyone done this?  Am I in for a world of trouble attempting such things?

I know in my boat and on my old RV the house batteries ran all of the interior lights and creature comforts while the starting battery only ran the stuff required to start and maintain the motor.  Then you have a momentary switch that will allow you to use the house batteries to start the motor if the main batteries are dead.  You can also get isolation chargers if need be, but with a generator, the house batteries can be charged via a regular charger/DC converter.  I plan to run 2 - 6V golf cart batteries for the house batteries as they are the best suited for the job and cost less per Ah than 12v deep cycles. 

Thanks,
Vern
PD-4104-772 in Central Florida

[Newbob]

That's a pretty deep subject (no pun on deep-cycle) :-)

I have done projects like this and they were not too bad but I did it with previous knowledge of both systems (not an expert though) and no urgent deadline. Every vehicle is different but it will largely depend on the space you have to run wires and such - the rest is mostly planning. Are you starting from an empty bus? are you gutting/remodeling at all or just trying to work around a finished interior?

[mung]

Interior is 95% finished by the PO.  don't need to add much in the way of stuff inside, the big thing is separating the two systems at the wiring buses. The wife would like the reading lights working, currently there is one that works and the rest may just be bulbs.  The lights on top of where the luggage racks were (now cabinets) seem to work well.  There are a bunch of RV style lights that work when it is plugged in and I haven't checked to see if they are running off of the old Phillips charger/converter or if they are 110.  There are currently no house batteries so the RV style lights are 12v they are running direct from the Phillips. 

Vern
PD-4104-772

[Boomer]

Like most commercial buses the GM's wiring contains relatively few circuits dedicated to the actual engine controls and exterior lighting.  Most of the circuits have to do with heat/AC, blower motors, the AC engine, etc.  But the wires were not numbered, the fabric insulation had a design on it to distinguish what they were for.  An OEM wiring diagram is essential for this project.  I didn't worry on my Silverside, I removed ALL the original wiring.  Big job ahead of you.

[TomC]

I lucked out with my AMGeneral-in that it is a normal 12vdc chassis ground system. I removed the 2 8D starting batteries and replaced them with 2-31 starting batteries. They have worked just fine since the 8V-71 usually only takes 1 second of starter to get it running. I don't run in cold weather. But if I need extra, I have a jumper relay. It consists of two 150amp continuous rated relays that are strapped in parallel to handle the up to 300amp Delco 50DN alternator. I have a dash switch that I can either select the relay to activate with the deep cycle batteries, or through the ignition switch with the starting batteries. In this way, if one set of batteries are dead, I can use the other to activate the relay. The jumper relay serves two purposes-one to charge the deep cycle going down the road, and to be able to jump start myself. I have been able to jump start myself with the jumper relay when the starting batteries went dead. Simple, yet effective. Good Luck, TomC

[Newbob]

Jumpstart yourself, huh Tom? - That's one rugged pacemaker you got there (-:

[mung]

I have the wiring diagrams that are included in the manual downloads, plus some hand drawn ones that were stuffed in my paper manuals found on the bus.  Might get me part of the way there.  I am not going to be running the coach AC (anyone need any parts from it?), so I don't need any of that junk connected.

[gus]

The 4104 int lights are originally carefully separated from the other circuits. If these haven't been altered it should be easy to wire them separately to the house batts. Mine was already done but it is a mess.

Those circuits originally are all on separate relays which makes it much easier.

[mung]

Very good.  I am going to be trying to work through it all starting tonight.

[Bob & Tracey]

I just did this to our 4104, not too bad of a project.

[Bob & Tracey]

Vern,
You can email me at ricekrgrATyahooDOTcom.