Wiring!!! And now I understand why the first thing most of you do is gut it.

[zubzub]

There where so many gremlins on my bus, thta it was almost impossible to trouble shoot any thing.  The old relays and breakers seem to work half the time, and the other half of the time they trip each other into forming new circuits.   Oil Pressure/generator/ and coolant temp don't work. I have no idea what the POs have done, but it has been hodge podge for sure.  My thought is that I should run a bunch of  50' extensions to the rear  of the bus, rip out  all the circuit boards/fuse panels and start fresh, using new relays etc....  How complicated does it have to be? .  All I need back there is lights, starter, kill switch, oil pressure  and coolant temp.  Same for the dash, I could get new guages, run the wires to the fuse panel and use it as a junction box, get rid of the rats nest  there, a few flashers etc  and I'm on my way.
I guess my questions are,
1.will this be easier than tracing all the POs and old wires? 
2. Is there a good way of running a bundle of wires from the driver's fuse panel to the left rear electrical panel?
3. Also if the coach has been converted to Neg ground, do the coolant temp and oil pressure guage need to be altered? How about the sending units on the engine?
It's a 4104.   Patrick.

[TomC]

Considering the age of your 04, it would be a good idea to rewire, and to make a new schematic of the wiring.  I ran 5-3 wire extension cords of different color from the drivers seat to the back of the bus.  Since my bus is a transit and can have the entire engine/transmission cradle removed for service (I think an 04 is like that, but not sure), I cut the extension cord in two about 5 ft from the male side.  Then the plug will be near the engine firewall so that if the engine has to be removed, just unplug everything, and will be easily rehooked since they are all different colors.  So far I've added cruise control and a tachometer with the new wiring.  My wiring is alright for the moment.  Good Luck, TomC

[TomC]

I forgot- if it hasn't been converted yet, this would be the time to convert it over to negative ground.  Good Luck, TomC

[gmbusguy1]

Patrick, are you just trying to get the 04 home or repair it /rewire it right?

I rewired an 04 last year and gained a lot of info as to the factory wiring


also Do Not operate your bus or any 2 stroke diesel without a emergency air shut off in working order and tested

you don't have to ask me how I know about the emergency shut down

Chris

[zubzub]

Both really as home is 1000 miles away, I need all the guages up and all the lights as well.  I would be interested in your info on the 4104 rewire, any chance you have a schematic?  Did you use the old wires or run new ones?  Any info on my question 2 and 3?  thanks, Patrick

[gmbusguy1]

Yes we have a schematic but you need a computer to be able to read it close up and identify the poorly hand written numbers from 19??

I will email it to you

the 04 I worked on had very good original wire front to back it looked new except the color used for the code was faded

the drivers electrical compartment and dash were a complete friggen mess as was the rear wiring from the rear panel behind the right rear tire
so I rewired the front, dash and rear along with the Michigan marker lights and installed all new LED lighting
it was a rather long And tedious job but was very worthwhile and everything worked great

i will find the photos taken of the project and send them along to you

if I can help in any way at all call me at 231 846 0880

Btw if your plywood floor in front under the drivers side window is soft or rotten replace the floor before doing the permanent wiring

Chris

[gus]

Zub,

I had much the same problem with my 4104. I copied the manual illustrations and listings, removed the front panel cover and instrument panel sections so I could get to everything.

I spent a lot of time tracing out wires, many of them not connected to anything (Which I removed) and finally got things working.

The cause of most problems was corrosion at the front and rear panel terminals (mostly the front) and the wiring near these terminals. I replaced most all brass terminal nuts and washers or cleaned the brass nuts and terminals.

You will find that a lot of the problems, especially with the instruments, are with corroded ground wires. This is a two wire DC electrical system.

The end results were that most things worked as they should except the alarm system which I don't worry about because I watch the gages closely.

I second the comment about the electric switch for the emergency shutdown, this is a must and can be checked with the engine off and engine run switch on.

To completely rewire this bus would be your worst nightmare even if it is completely stripped. You can't really imagine just how many connections and wires there are.

One of the biggest problems is figuring out all the wires added by POs. My guess is that they just gave up trying to figure out the problem and bypassed the original wiring, this happened quite a few places on my 4104 and the same things happened to the air system. Not at all surprising considering the ages of these great old buses.

[JackConrad]

   If you are going to rewire the bus, go to www.waytekwire.com and check out "trailer cable".  There are several cables availalbe such as seven 14 gauge, six 12 gauge, or a combination of two 10 gauge/one 12 gaauge/four 14 gauge. These are the 3 cables we used, they also have a couple other combination cables. Wires in each cable are color coded.   These cables are for 12 & 24 volt wiring, not UL apoproved for AC iuse.  Jack

[Len Silva]

Zub,

I had much the same problem with my 4104. I copied the manual illustrations and listings, removed the front panel cover and instrument panel sections so I could get to everything.


The end results were that most things worked as they should except the alarm system which I don't worry about because I watch the gages closely.

Gus,

Most likely the reason your alarm system doesn't work is that the alarm rectifiers were not changed when the system was changed to negative ground.

Len

[John Z]

Hey Chris,

Do you remember what kind of LED you stuck in your Michigan marker lights? That is one of the things i will want to get done this spring, or who knows, maybe even do it when i am on my Feb trip to LA.

Thanks guys for the good tips on the trailer cable and using different color 3-conductor cords,,, i am going to remember those!