Detroit Diesel 6V71 wiring question

[Simy]

I have an 86 Neoplan AN340/3 (I'm guessing on the model number, the title is blank for model, and I can't seem to find any tag anywhere in the vehicle)

The wiring was butchered when a PO removed the factory AC, I've been slowly trying to correct it but have basically decided to give up and just rewire it. This was fine until an odd thing started happening, my left front blinker is off when every other light is on during a flashing mode. (left turn or hazards) I thought it was a bad ground as a previous incident was, however it isn't. This is an of itself is no big deal but since this started I can't run the bus AND have the lights on, even if I use the switch from the back. My end goal is to rewire the entire bus and make it very smart using PIC microcontrollers, a Raspberry Pi ARM PC, and lots of sensors/gadgets.

Most of what I want to do is really just eliminate what seems to be like a good 50-75 wires running front to back - and have a wiring diagram I can reference if a future problem happens.  I'll have at most 10.  I plan to run some sort of 2 or 3 wire communication system to link the master with the nodes. I can't currently leave the bus where it is for long. I can work on it when I have time, but then I have to put it back in storage. I can't have it at my house for more then 30 days. So this has stopped me from just ripping every single wire out, and starting from square one. The problem however is that I keep getting electrical issues, I have spent an alarming amount of time just trying to fix the existing wiring, and while trying to trackdown (and failing) this recent issue I have what seems to be a nearly electrical gadget-ed engine! There are what I think are sensors for engine temp, coolent level, and oil pressure as near as I can tell, and what looks to be a electro-pnumetaic type actuator. I don't exactly know what this device does but I do know that if it has power, it will click on, and the engine will be able to run/start.

As bad as it sounds, I don't care about the sensors currently, I'll cross that bridge when I come to it, the question really comes down to this, can I rip out all the wiring, connect that 'run clicker', and then hook up a momentary switch for the starter and drive away? The storage is only a half mile from my house, and I know how to manually move the pneumatically actuated shifter from gear to gear.


I'll have to look more at the transmission but can it really be that simple? Will I damage anything by disconnecting every sensor/wire I see in the engine bay and attempting to jump the aforementioned parts? I'm fairly sure I don't have a DDEC -- and even though I'm a techno junkie, I'm glad =)


Sorry I'm long winded but I wanted to give as much information as possible. If you have anythoughts or suggestions on controlling the engine this way I'd be glad to hear that as well.

Also, I've finally found a reason to say hi, so 'ello We've had to delay our full timing adventure due to rust, and wiring, but rest assured about this time next year we should be ready to go

I don't actually have a picture of the box that clicks to start it, but I can get it if its needed. Thanks for any advise/comments/suggestions

PS: The reason for all the wiring/microchips is I'll be able to control almost any/every function from a tablet, smartphone, or any wifi device =)

[luvrbus]

Start it and drive away just be sure to check the water and oil it won't run without fuel,shift the transmission by hand that has a Bennett shifter and is not going to hurt a thing shifting it manually and no you do not have a DDEC on  6v71 

good luck and the best to you on the wiring  

[Simy]

Thanks for your very quick response, I'll get started on that tomorrow and let you guys know how it goes.

[Dave5Cs]

We like pictures as if we are in your classroom and learning with you.

Dave5Cs

[Gordie Allen]

I faced the same issue when I started the reconversion of my bus, a GM 4104.  It has a 6-71 as well.  It had hundreds of feet of wire, most of which no longer served any function, and a "fail safe" circuit that would shut the engine down if low oil pressure or high engine temp, etc. occurred.  I have the original maintenance manual and the schematic for the system was crazy - amazing, but crazy.  If any of over 20 points in the system failed, the engine would shut down and finding the fault would be a nightmare.  Since a 6-71 only needs fuel and a starter to fire, I gutted all the wiring, and started from scratch.  Best decision I've made so far.  All you need is an Engine ON/OFF switch which controls the relay to the fuel supply, and a momentary switch to a relay that controls the starter solenoid.  On the GM, both relays are in the back.  I just hot wired to the original relays to find out what did what and fired her up.  I then replaced the wiring, switches and relays with new stuff.  The other two relays I had to trace and replace were for reverse (I have the 4 speed Spicer) and the high idle relay.  Both the fuel supply and high idle relays go to air supply valves that then open fuel supply to the injectors and activate the high idle air cylinder.  I have two fuse blocks in the driver's panel up front.  One panel is only hot (via a relay) when the Engine On switch is activated.  Anything you want to turn on or off along with the engine, you wire from that block, like the relays mentioned above, dash gauges, dash lights, windshield wipers, etc.  The other block is hot all the time, so things like emergency flashers, marker lights, head lights, courtesy lights, backup lights, etc. would be supplied from that.  So, I have all new wires, switches, relays, gauges, sending units and lights.  The only things I didn't change out were the heavy primary cables.  All of those were in good shape; although, I did have to add more for my house battery / MultiPlus hookup.  Also, I laid all my wiring (ac and dc) in a 4"x4" raceway down the driver's side wall and across the back floor of the bedroom to the rear electrical panel - inside the living space, so I can get to any wiring anytime with easy access.  I "borrowed" my wife's Brother Label Maker to label all the wires at both ends and all the fuses and relays in the front and rear panels.  I also drew a wiring diagram on a note pad as I went and then transferred that to a diagram I have on my computer, which I'll print out and put in my hardcopy "Owner's Manual" so ten years from now, I can look up what I did 'cause I know I won't remember it all!
Good luck and just take it one wire at a time.
Gordie

[Simy]

For pictures I have a blog which shows my current progress, I try to update it every 2-3 weeks. http://maxrving.blogspot.com/
I'll be putting up a new post soon, I've taken quite a bit more out of it yesterday to be able to see how big of a rust problem I have. Not to mention the wiring. I try to space it out a bit though, to keep it more interesting.

[Simy]

Well its too rainy and dreary out today to really do much so we ended up taking the bus back to storage, hopefully I'll get my PIC microcontrollers in before next weekend and I can just wire them up the way I'd like to to start with.

I do see a few wires I'm unsure of, these look like they are from the generator/alternator. I see some air lines, the main power cable, and then 3 more cables running to it, does anybody know what these do? Picture attached this time =)

[akroyaleagle]

I am not an electrician! I especially hate DC.

Do a little cleaning around the terminals and I think you will find FLD (field) and some other
stamped things. It will be easier to answer if we have that info.
One of them may run a tach. One probably goes to the voltage regulator.
Should be one to a relay for the batteries.
Follow them to find out.
The solid lines may be lube although they look very small for that. it is difficult to tell from the
picture.

I would discourage you from "Just ripping Out" wiring. Better to get a wiring diagram.
On buses, many electric things seem to be interconnected. Many old transits won't start to move
if the connection is not closed for the side door. The door may have been long removed. Etc.

Good Luck,

[luvrbus]

That is a standard set up for the Delco 50 the line is a oil line not a air line, big cable goes to starter,you have a field,a relay, the ground and the regulator wires pretty basic