The more I learn The less I Know!

[NewbeeMC9]

Is the Bus interior stripped out?  That would make it a lot easier.,  then you can check the frame and insulation etc.

[tpboj]

Well I spent some more time tracing wires and have started pulling the everything out. The interior is all out by previous owner.
The fun with an old bus is every day is a new surprise. In tracing the loom under the floor I found the last owner thought he could fix rotted wood with Bondo. Well at least I can get to the loom now that I pulled the whole floor out.

Thanks for the help.
Tom

[Hartley]

12 volts is an easier standard to get things for. The only drawback is the amps are double that of a 24volt system, so the wire size may need to be larger to avoid voltage drop problems.

You have done custom cars - so, you're over half way there, just study up a little on the load isolation relays & you'll be all set.

The problems I have in following the factory bus electrical schematics are many & include;
- was designed with an emphasis on economy of materials which leads to some very confusing current paths for non-electrical engineers. 
- included many things not needed if you're not hauling passangers- so the stock circuits are no longer sized correctly.
- obtuse junctions & ground paths.


By all means, look at other wiring diagrams to get ideas.
Gather some schematics from motorhome manufacturers - compare the differences from the ones that are built on a purchased chassis VS. the ones built on their own custom chassis.

Have fun!

If it is a true scenicruiser PD4501 it was originally a 12 volt positive ground system, Later they rewired for a negative ground system on most. That apparently didn't take much to do since
electronics and computers were only just getting started.

Go with the 12 volt system. then your house system can also be 12 volts and can be switched to charge from the bus alternator more readily.

Gotta remember too that the original PD4501's had 2-engines sitting side by side so there is still
all that additional wiring in there to confuse and amaze. They didn't get the 8V71 engines until somewhere around the late 60's to early 70's ( I think?? )

Imagine the racket that 2 4-71 engines made. I loved that sound when I rode them in the 50's & 60's ... Up Hwy 301 across Mt Airy NC.... Very cool ride at night...

[TomC]

I believe 1958 is when Detroit brought out the V blocks.  Around '59-'61 is when Marmon-Herrington brought the 1000 buses in and exchanged the 2 4-71's for the 8V-71.  So the actual usage that those buses were using the twin engines was short lived.  On paper it was a good idea, but without the aide of electronics of today to manage the power, the driver's were not up to the task of keeping the bus running smoothly down the road.  Having a 3 spd trans with a two spd splitter was just too much-throw in the option of being able to cut out one engine on the flats-too much problems.  The simplicity of the 4 spd with the 8V-71 has been demonstrated by the billions of bus miles over the years with that setup.  The only problem from our stand point is that first gear isn't low enough for some of our exploring ways.  Course, in my opinion, switching to an Allison takes care of all that, and some fuel mileage.  Good Luck, TomC

[Hartley]

Tom,

I think you are probably correct on the timing of the greyhound fleet changing over, I had heard that it was in the 60's but it may have been in the late 50's and early 60's..

Sorry. My apologies to anyone that may have been confused by my random thoughts... My brain is somewhat damaged more than usual lately.

Dave...

[kyle4501]

Yep, it was 1961 & 1962 when they Marmon-Herrington did the first rebuild of the 984 Scenicruisers still in service. 17 had been lost due to collisions by then.

The rebuild included repainting the bus inside & out along with new insulation & floor covering. When M-H was done, it was essentially a new bus.