I am going thru a dead shift selector panel issue.
According to the dealer mechanic who has serviced this bus many times when it belonged to the school board he indicated the pink wire #124 tends to break open near the transmission.
Here is a cut and paste from the above (link) tech tip.
Instructions for WTECIII system [ single red digit on Your shift selector ]
Have You recently replaced battery and accidentally swapped battery terminals? If "YES", ECU maybe fried beyond repair. If "NOT", locate the ECU (in most RV's is near shift selector, close to VIM Module or, mostly on Trucks, close to transmission - just follow bundle of wires from transmission). Disconnect the battery first, then unplug all three connectors from ECU and reconnect battery. Closely check the GRAY connector for numbers. Insert test lamp leads into corresponding connector sockets: 1 and 32 then 16 and 17.
Next turn "ON" Ignition switch and insert test leads to 17 and 26. If cavity #26 is blank, use BLACK connector socket #4. Lamp must glow brightly.
#17; #32 = BATTERY GROUND; #1; #16 = BATERY POWER; #26 gray or #4 black = IGNITION
Next turn ignition and battery "OFF", reconnect GRAY ECU connector only, then reconnect battery and turn "ON" ignition. Then very carefully touch gold plated pins #16 and #32 [ on ECU for BLACK connector ] with lamp test leads. Lamp must glow bright. Then use a Voltmeter to check 5V on pin #3 [ on ECU for BLACK connector ] against chassis ground. DO NOT use test lamp!!! If no 5V is found on pin #3, ECU is defective.
Also check socket #3 on BLACK connector with Ohmmeter against chassis ground. Must be Must be over 4k ohms.
Shift selector can be check using ordinary 9V battery and hookup wire. Connect the 9V battery using hookup wire, which you may have to slightly bent on the ends so they can hold inside BLACK connector sockets. Connect Minus terminal to #32 and positive terminal to #3 and #16. After power "UP" all segments and RED LED [ Mode ] will be illuminated for 8 second and then display will show " cat eyes ". If one pushbutton "D","N" or "R" is hold down during power "UP", display will show "d", "N" or "R" for 2 second only. This way, You can check pushbutton switches.
If display will not be illuminated, maybe defective shift selector or harness. To check out harness, You must disconnect connector located
1/2' from selector. Then remove strain relief [black plastics ] from on vehicle harness connector and check closely rear side for letters.
"P" = GROUND "R" = POWER "N" = SENSOR POWER
Insert 3 short lengths of hookup wire into sockets "P", "R" and "N" and use a voltmeter to check voltage between "P" and "R" and between "P" and "N" if You using 9V battery. If ECU and battery still connected, insert lamp leads to "P" and "R", then turn ignition "ON" and with voltmeter check for 5V in socket "N".
If You do have voltage and there is no display, shift selector is most likely defective. If You do have voltage on ECU pins and not on the shifter connector, a defective harness is indicated.
Check continuity with Your Ohmmeter between "P" and chassis ground. Should be less than 1 OHM. If the meter reads "open", (Infinate resistance) find a good ground in the cabin, cut "P" wire 3" from connector and reconnect with new ground.
If missing 12V - "R", found "ignition" power, cut "R" and reconnect with "ignition" power. If missing "N" [ 5v ], cut "N" and reconnect with "ignition" power.
12V will not damage the shift selector. If one of three last steps will power up the shift selector but no response to commands, You may have additional harness damage or defective ECU or shifter. In this case, You can send ECU + shifter for free testing [You pay for shipping only].
Oh yeah, my first post...finally bought a bus!
Drove it all the way home from Louisville to Miami without a hiccup only to get back in it a few days later and it won't start. Check Trans light is "ON", on dash.
Take a look at the pics I attached.
These are the steps I took as outlined in the above tech tip.
Quote:
If display will not be illuminated, maybe defective shift selector or harness. To check out harness, You must disconnect connector located
1/2' from selector. Then remove strain relief [black plastics ] from on vehicle harness connector and check closely rear side for letters.
"P" = GROUND "R" = POWER "N" = SENSOR POWER
Insert 3 short lengths of hookup wire into sockets "P", "R" and "N" and use a voltmeter to check voltage between "P" and "R" and between "P" and "N" if You using 9V battery. If ECU and battery still connected, insert lamp leads to "P" and "R", then turn ignition "ON" and with voltmeter check for 5V in socket "N".
If You do have voltage and there is no display, shift selector is most likely defective. If You do have voltage on ECU pins and not on the shifter connector, a defective harness is indicated.
Check continuity with Your Ohmmeter between "P" and chassis ground. Should be less than 1 OHM. If the meter reads "open", (Infinate resistance) find a good ground in the cabin, cut "P" wire 3" from connector and reconnect with new ground.
If missing 12V - "R", found "ignition" power, cut "R" and reconnect with "ignition" power. If missing "N" [ 5v ], cut "N" and reconnect with "ignition" power.
My problem was with my "R" wire/position on the harness. It is pink and on my bus it is wire # 136.
When I testesd "N" & "P" I found 5 volts - good! "P" is ground and "N" is positive voltage.
When I checked "P" & "N" - nada, no voltage.
"N" is wire # 124 / pink in color. This is the wire the mechanic told me to look for. Turns out it was "R" wire # 136 which was open inside the connector. When I took the connector apart I saw that the gold pin was on the wrong side of the connector.
Reconnected the Transmission ECU, turned the key and now I have power to the push pad!
Charging batteries on the bus, starter now clicks but not enough juice to spin!
After reading many postings on the internet it seems that this is a common problem that could be a PIA to troubleshoot.
First thing I learned after going nuts looking for it, the VIM - Vehicle Interface Module on an Amtran bus. You will not find it like many posting suggest for Rv's or Trucks.
Look in the Passenger side, engine compartment, big black box with the rear start key switch...six or seven relays and fuses....That is the VIM. Look no further.
Transmission ECU is tucked between the frame rail and transmission, passenger side of bus.
Push Pad on dash, cable goes straight down to the floor then hugs the driver side frame rail all the way back to the transmission.
The connector that had the bad wire, just before the connector that goes to the tranny itself, driver side.
I have attached a homemade drawing of the female plug to the dash pad and also attached a wiring schematic for a Thomas bus which helped me out tremendously.
If anyone finds themselves in a similar situation, do not fret, follow the instructions on the tech tip from Transmission instruments, it was right on the money!
super write up! ive read about that MD3060 issue before.. and otherthing that hapens is water gets into the connectors sometimes. and causes issues.. fortiunately yours was just a bad power wire and you got it going!!
-Christopher
Yeah, +1 on your patience and on your chops! It's not often that a new member with some variation on "dead bus syndrome" finds the right troubleshooting information and works it to a successful conclusion, especially a really non-obvious problem like yours. Read the back stacks for epic battles where we've tried to assist somebody via the medium of ASCII characters. 3 cheers for you!
I'll add that WTEC-3 (WTEC-III) is just a fancy name allison gave to the industry standard CAN-BUS protocol J-1939. even the older electronic engines.. (T-444E(97-newer),DT-466E, CAT-3126) and others. are able to utilize any Allison electronic transmission without special considerations.. you simply connect up the CAN 1 pins on your Allison TCM to the CAN pins on your engine ECM and your transmission will receive raw throttle data..
if you reprogram your ECM for an electronic transmission.. (in navistar you alter the parameter to 'allison MD'.) then your transmission will receive even more data..
you can also install a J-1939 scan tool to that trans link without having an electronic transmission and you can receive various engine parameters.. (J-1939 scan tools are more common than J-1708 (the diag connector on older engines is J170.
also to be noted is that installing a J-1939 scan tool in the data bus that your keypad and transmission are on, you can receive the trouble codes from your TCM (if you have an allison 2000 you dont have a digital keypard but the link is still there)..
Congratulations on chasing out that gremlin, well done.
Oh, and welcome to the uncertainties of everyday bus life!
John
Looks like the gremlins came out last night and set me back to a no start condition.
When I turn the key to start, you can here starter engage and try to spin but it doesn't spin.
What I am noticing, in the "VIM" box, the relay for the "neutral start" clicks constantly which in turn the starter solenoid engages and disengages as this relay clicks on and off, so you hear and see the motor "kick" as it tries to spin, but doesn't.
Almost like what a dead battery does when you try to start a motor but it doesn't have enough juice.
I have super cleaned all the terminals and put on a battery charger while I work... Nada, zilch....
This relay gets it +v from the ECM, gray connector pin #6 and the ground signal comes from the battery and is also tied to the ECM at pin #17 (gray connector).
So what is making it get such an intermittent signal... A high open on any one of these two wires???
Checked with a light bulb, no dim lights, bright light so no high open present.
Have you tried a different relay in place of the one that is on/off/on?
Can you see the space in the block that relay plugs into? On the back if you remove it you will likely see green, corrosion on the connections.
Worth checking but also sounds like your batteries aren't up yet.
Just some initial thoughts, I'm sure your connector from yesterday is tight and making good contact. Maybe move the shifter as you do the start procedure, might be out of adjustment.
Turned out that one of the two batteries developed a short in one of the cells and it was killing all the amperage it needed to spin.
Replaced the bad battery with a known good used one and ...voila...it cranked!
This after rechecking all my connections....
I should have remembered step #1 when troubleshooting any and all electric circuits, confirm that the power supply is good before proceeding to step #2.
When it comes time to get new batteries check around for a Rural King. They have decent batteries for $75-$80 each.
I've been using them for years now.
When it comes time to get new batteries check around for a Rural King. They have decent batteries for $75-$80 each.
I've been using them for years now.
Glad you got it running!!
Yeah, I'm definitely gonna put in 2 new batteries, for sure!
But now I have another issue...
Man the gremlins are out to get me today!
When I put it into drive or reverse, check trans light comes on and bus does not go into gear.
Can't even pull codes on the dash pad, does not recognize my pushing down on the 2 arrow buttons twice for codes.
I bet I got another bad wire in that same connector.
Back under the bus I go!
Well at least it starts now, this should be somewhat easy now.
Hope my ECM didn't get damaged....
I called transmissioninstruments, the folks who published the tech tips I posted. The guy there named Vojta (pronounced voita) told me when the WTEC 3 fails, it fails completely!
He told me my problem was most likely with the serial communications to the ECU.
The simplest thing to do was unseat the two round gray connectors that I had previously disconnected, under the dash and next to transmission where I fixed the bad wire, visibly check the pins were not bent or broken.
If that was good then the next step was to check continuity on the serial communication wires from the push pad to the Black connector on the ECU.
Well I got lucky, I after doing the visible check on the pins and reseating the connectors, I started bus and got it into gear, bus now moves!
So we have a new twist on the bus (9906), she starts fine but won't go into gear either forward or reverse. Also when I depress both the up and down buttons at the same time it will not go into diagnostic mode.
I am continuing this thread because I want to share what I am learning along the way and hopefully someone will chime in with a good answer to the problem. I also want to encourage all with an Allison push pad to follow along because one day, it can happen to you !!!
The original problem was a broken wire and I have finally identified what that wire was and what was its function.
It was wire #136 which is pink in color and its function is to supply VCC (voltage) to the push pad. The wire was broken inside the connector causing the dreaded dead dark panel.
So todays problem is quite baffling. I have power to the push pad, it is communicating with the TCM as bus does start up now.
I have printed the pinouts for the wiring system of a WTEC3 and uploaded for all to have. Again, you may not need it today but when it goes down, good luck finding someone who might understand this system.
I am trying to figure out a plan of action on this, how do I proceed?
One thought is to tone out the wires in the "S" Black connector. If that is all good then I will tone out Blue connector.
The gray connector wiring is the simple easy one to do. The Blue seems like a bit more complex.
So this packet of info that I am uploading contains the abbreviation and connector names, basic shift selector wiring, general description of the three wiring harnesses and the pinouts the the three system cables, "Black", "Blue" and "Gray".
somewhere along the way I hope to get into some detail on how all this gets tied together...but once I get it back into gear...I'll put this to hopefully a long dormant rest!
What I got to figure out is how to make a test jig so I can test continuity on the wires as a one man show.
ewo1, thank you for posting that information. I may need it one day too.
As for a continuity tester, do you already have a multimeter with a tone function?
I have a collection of long leads that I use when alone- which is always. The longest is about 30 feet.
Some have alligator clips on each end, some with alligator on one end ,banana plug on the other, and some with little spring loaded hooks on them which are good for grabbing pins inside harness connectors.
The long leads don't cut down on the number of trips I have to make from one end to the other, but they work.
ewo1, thank you for posting that information. I may need it one day too.
As for a continuity tester, do you already have a multimeter with a tone function?
I have a collection of long leads that I use when alone- which is always. The longest is about 30 feet.
Some have alligator clips on each end, some with alligator on one end ,banana plug on the other, and some with little spring loaded hooks on them which are good for grabbing pins inside harness connectors.
The long leads don't cut down on the number of trips I have to make from one end to the other, but they work.
Rich
What I was considering was purchasing the the matching round connector and wiring it up in such a way that I can jumper two wires on one side and the with an analog ohmmeter test on the TCU side with has the flat connector.
If the jig I build is successful then that would become a must have diagnostic tool for when rolling down the road. That's the plan, let's see how it plays out.
I fixed the problem! Got drive and reverse to work again!!!!
Solution - another broken wire found "INSIDE" the deutsch connector!
So after a week of studying the troubleshooting manual diagrams I went ahead and created my own diagram for testing purposes. What I have learned and identified is the wiring colors, wire position numbers and their functions.
Mine is a WTEC3, single digit display.
What I did and the simple way to tone the wired out, by yourself, is to jumper the wires on the female connector right at the push pad itself, or should I say the female connector of the wire from the push pad to the transmission, not the tcu.
I used a thin paper clip for a jumper. Then i went under the bus, to the tranny connector, and tested for continuity.
The WTEC3 uses 5 control wires, 3 power wires and also a general output wire.
My hand drawn diagram will show you which wires are what and where they are located.
So I started by jumping Blue and Yellow, testing at the tranny connector, good continuity.
Then I went to Green and Orange, no continuity!
I tested the other wires using the same method and found the Green wire to be open at the connector. spliced the wire outside the connector, bus now goes into gear !!!
The connector at the tranny, look under your bus on the driver side (RE BUS) and you will see on fat cable that enters the transmission housing and about 6 inches away there will be a Deutsch connector there mounted to a bracket. that is not the connector!
If you follow the cable it will go into a "Y" and right there it will branch off to another Deutsch connector. That's the one!
To confirm, the other end of the cable will go to the front of the bus to the push pad.
It still won't go into diagnostic mode but that's a challenge for another day!
.
Man the gremlins are out to get me today! 
Linear Mode
