Having a challenge with our 99 MCI 6V92 A103.
Last couple of weeks seem to having something going wrong with the neutral safety - getting it set so bus will start. Today finally could not get it to start at all.
Is this neutral thing a component - switch or connector? Where is it located? Can it be replaced or fixed? Where can we get the part?
Also need help finding the diagnostic port to plug in to run diagnostics. Cant find anything in engine compartment. Called MCI tech support. They said it should be under dash to left of steering wheel. cant find anything there either. Does anyone know where this connector port is?
Appreciate any and all help
Thank you
Joe
Probably a 102A
Yours may be different than my 5C. Should also be a neutral relay in same box. Look in your maintenance manual about chapter 7 IIRC.
What part of the country are you in? Might be a Busnut close to you.
There is a port in the front bay driver side where the AC relay are just open the door on the tunnel,? what transmission electronic transmission don't use a neutral switch on the transmission it is in the pad or shift tower
thank you guys!!
I am in Central PA
Yes, you are correct, it is a 102
either a fat finger entry mistake or brain malfunction on that
when you say in the pad. Not sure i know what you mean by that.
Understand the shift tower is the box where the shift lever is located.
Just had the gear indicator stop moving when we shift. Is that a problem?
Is the transmission and engine electronic control ? they can have a shift tower or a push button pad for selecting gears on a electronic control transmission help us out man 8),I don't think you have a 1999 model 102A maybe a 1989
Neutral switch can be in the side of the transmission if it is an automatic
Quote from: Templar52 on November 11, 2018, 12:32:58 PM
Neutral switch can be in the side of the transmission if it is an automatic
If he has a Allison World Transmission where does the neutral switch mount ? on the side ,a 1999 model should have a World Transmission or another brand of electronic transmission if a automatic
Thanks again for the help.
Still may need more help with this. To follow up. The system is DDEC 6V92, with automatic transmission. Shift lever is to right of driver seat in a tower type of mount. 5 speed.
What am i to look for on this neutral control switch? Is it a unit that we may need to replace, or something that can be repaired?
The manual i have on this seems to be incomplete. The bus is a 96-102 series finding lots of pages missing. The section for the transmission is chapter 13. But the pages i have are for a manual transmission. pages for the automatic are missing.
Just my luck
keep going...
What transmission model is in it?
The stickers on the shift tower doesn't tell us what's actually hanging under the bus back there.
Crawl in/under there with a rag, take a picture of the tag and post it here.
Can't help if we don't know what you got...
happy coaching!
buswarrior
You MCI guys help me out I am having trouble figuring out what bus he owns, the A went out of production in 1991 right,the C ran from 1988 till 1993,I believe this guy has a D or the MCI 12 a photo would be nice because a 1996 model will be a 4 stroke engine the 2 strokes left the market in 1994
95 to 99 was a 102 D and DL3
88 to 90 was 102A
88 to 93 was 102 C3
Was also a 102B in 85 but short lived.
I have a copy of the Transmission section that you can look at depending on what model your bus is. But for anyone to fully help, we all need to know the complete model
Is it a 102A2, 102A3, 102B3, 102C3? Year as well
Thanks again for the help.
Still may need more help with this. To follow up. The system is DDEC 6V92, with automatic transmission. Shift lever is to right of driver seat in a tower type of mount. 5 speed.
What am i to look for on this neutral control switch? Is it a unit that we may need to replace, or something that can be repaired?
The manual i have on this seems to be incomplete. The bus is a 96-102 series finding lots of pages missing. The section for the transmission is chapter 13. But the pages i have are for a manual transmission. pages for the automatic are missing.
Just my luck
Quote from: jraynor on November 12, 2018, 03:35:20 AM
I have a copy of the Transmission section that you can look at depending on what model your bus is. But for anyone to fully help, we all need to know the complete model
Is it a 102A2, 102A3, 102B3, 102C3? Year as well
some additional clarification.
The bus is a 1988 MCI 102 A3. DDEC 6V96. Auto transmission - Allison 4 speed.
So your bus is only a few years older than mine. seems like the only thing different is the fact that yours is a DDEC. Send me your email in a personal message and ill send you the transmission section that I have to see if I have the missing pages you need. In the mean time I will look at some schematics to see how the neutral plays into starting to see if I can locate where the switch is
Email is: joe.delauter@homeinstead.com
The manual i have - cover page has following: MCI 96-102 series model, Maintenance Manual. TMC, Roswell, NM, Custom Coach, Columbus Ohio, MCI Pembina, North Dakota, Universal Coach Parts, Inc., Des Plains, Ill.
Ok,it has a 740 Allison the neutral switch is on the drivers close to the shift linkage it has 2 wires pull the wire and use a paper clip to jump with and if starts the switch is bad and he won't have a DDEC engine unless some installed another engine.A 88 model would have been a DDEC 1 and I never saw a DDEC 1 in a MCI they used 2 -boxes on the DDEC l
Quote from: luvrbus on November 12, 2018, 05:13:06 AM
Ok,it has a 740 Allison the neutral switch is on the drivers close to the shift linkage it has 2 wires pull the wire and use a paper clip to jump with and if starts the switch is bad and he won't have a DDEC engine unless some installed another engine.A 88 model would have been a DDEC 1 and I never saw a DDEC 1 in a MCI they used 2 -boxes on the DDEC l
After looking at the diagram for the bus, I think the neutral switch is actually on the transmission itself. From rear junction box stud #24 or #25, a wire labeled 3-BK-16 (so its a 16 gauge) wire goes to the neutral relay terminal 7. This is an icecube style relay with only 4 terminals being used. From terminal 2 of that same relay, the same nomenclature on the wiring runs to the neutral switch and then to ground.
So with it coming from the rear junction box, I believe that its on the transmission. Plus I have looked in the shifter tower and I don't think there is a switch there that the lever hits. I know there is sometimes a switch there for the park break that is used for the retractable step
Jonathan,
Thank you,
The rear junction box. help me with this. Where is that box located?
The Neutral relay indicated on the diagram - is that a unit that we would replace?
On the tower, there is a separate area where there is the parking brake lever. It is a push pull type of knob.
Quote from: joedelauter on November 12, 2018, 05:46:05 AM
Jonathan,
Thank you,
The rear junction box. help me with this. Where is that box located?
The Neutral relay indicated on the diagram - is that a unit that we would replace?
On the tower, there is a separate area where there is the parking brake lever. It is a push pull type of knob.
open the side door behind the rear tag axle on the drivers side. it is to the left of the air intake. Not the easiest to really access and debug. And no, the relay is is not the item to replace, this is just what to look for to follow the wire that should lead out to the transmission to where the neutral switch is. That neutral switch may be your issue.
Just thought of this: Have you tried to shift just outside of the neutral position on your shifter to see if maybe the cable needs to be adjusted?
Thanks for sticking with me on this.
We moved the shift lever several times through the gears and jiggled it over and over. It did catch one time and started. Several days ago. But we cannot seem to get it to catch.
That is what led me to think that it might a a unit that can be replaced or fixed. But if it might be a cable, how do we diagnose this and then what is the process to adjust - correct?
Just take a light and look on the drivers side of the transmission at the linkage if you see 2 wires that is your neutral switch start there bypassing the switch, it relieves a lot of heart burn and saves a lot of time wasted chasing the circuit.To check the adjustment just hold the starter button down and move the shift lever in both directions.If the fuel pressure switch goes bad your MCI will start either
If this works, what would the adjustment be to correct?
Quote from: joedelauter on November 12, 2018, 05:58:38 AM
Thanks for sticking with me on this.
We moved the shift lever several times through the gears and jiggled it over and over. It did catch one time and started. Several days ago. But we cannot seem to get it to catch.
That is what led me to think that it might a a unit that can be replaced or fixed. But if it might be a cable, how do we diagnose this and then what is the process to adjust - correct?
I would troubleshoot the neutral switch first. you can bypass it more easily by taking the ground directly to terminal 2 of the relay base. Disconnect the existing terminal connection and connect the terminal to ground as shown in the picture. If it starts, then you'll have to go deeper into why the neutral switch isn't working anymore (or why its working intermittently) or adjusting the cable can still be the fix. I wouldn't mess with adjusting the cable unless you can repeatedly get it to work by slightly moving the shifter. (verification by reproduction)
If it doesn't start, then its another issue
We still need to find out if he indeed does have a DDEC engine I never saw one in that year model of a MCI but it is possible he has a DDEC a photo of the front top of the engine would clear that up,if he has a throttle cable with air cylinders on top it's a mechanical engine and he can stop looking for a plug in port
Quote from: joedelauter on November 12, 2018, 06:09:12 AM
If this works, what would the adjustment be to correct?
Joe,
Take a picture of your engine from the back with the doors open. Try to make sure you capture the top portion of the motor as well near the turbo. trying to find a picture with one and one without but im having trouble finding one
So I found these 2 images. The red engine is about as close as I could get to finding one with the DDEC. apparently DD mounts the Boxes in different places on the engines. saw a really good picture of one before but I never saved it
They are all mounted there on the 2 stroke engines they set on top of the governor
The picture on top looks like our engine.
I will go out and get a picture of the engine with the doors open and send it too you.
Also could use some help with finding an adapter for the port to plug into to run diagnostics.
Will take a picture that and send it to you.
Wont be able to get that to you til later this afternoon.
Appreciate your help and support and technical insight. (way beyond my understanding)
Quote from: joedelauter on November 12, 2018, 09:22:09 AM
The picture on top looks like our engine.
I will go out and get a picture of the engine with the doors open and send it too you.
Also could use some help with finding an adapter for the port to plug into to run diagnostics.
Will take a picture that and send it to you.
Wont be able to get that to you til later this afternoon.
Appreciate your help and support and technical insight. (way beyond my understanding)
if your motor is like the top picture that is the Non-DDEC so you shouldn't have a port for diagnostics
Oh - well, guess i may have been led down a path. Was told that it is/was a DDEC. The mechanic that we get help from said it was not a mechanical system but an electronic one.
Will get the pictures and send them to you later today to help bring clarity, truth and hopefully some closure to my lack of knowledge.
Hold fire 'til we get a picture...
Why am I reminded of a fire arms acquisition class where a participant didn't know what a trigger was?
joedelauter, please be careful you don't hurt yourself with that coach, your posts are scaring me.
happy coaching!
buswarrior
If grounding number two on the relay starts it then you know its the neutral switch if it doesn't start then I would bet its the Ice Cube relay that you just pull out from the neutral relay and replace. I just went through this and that was all it was.
Part # MCI 7C-5-24 (original relay) there is 4 of them on board.
New one=ALB700HA32Z24 RelayPlatt electric normally 24.00 each. I got them for 15.89 only because they found my old account I forgot I had and I told them Grainger had them for less. LOL ;)
Another number for it is;700-HA32Z24 TUBE BASE RELAY 24VDC
Ok so the engine is a DDEC. Joe sent me the picture and I have attached it below.
Should still be able to "jump" the neutral switch via the method described. Only thing I would be weary of is if the bus is in gear or not and you try to start it and it try to move. Yes the parking brake should be engaged but you won't be able to shut down the Detroit until it has air pressure to push the stop lever on the governor.
Another question is, does anyone know where the port to connect to for diagnostics is? Maybe under the front seat? That's what Joe is thinking. I'll let him chime in
That is a transplant engine no telling it may not have 1 just the SEL and CEL on the dash,now the DDEC ll is out of the way he needs to look on the drivers side of the transmission and see if we are dealing with a electronic Allison 700 series like a 741 if so they don't have a neutral switch
Quote from: luvrbus on November 12, 2018, 04:43:03 PM
That is a transplant engine no telling it may not have 1 just the SEL and CEL on the dash,now the DDEC ll is out of the way he needs to look on the drivers side of the transmission and see if we are dealing with a electronic Allison 700 series like a 741 if so they don't have a neutral switch
It's not an electronic shift pad. It has the same shift tower like mine. I've attached the pictures below. He did send me 1 picture of some cover under the driver's seat. Anyone know what that is?
Will wait for the mechanic to look at the wiring for the switch and whether to try to jump it.
Not keen on it starting and not being able to shut the motor off.
There is a box next to the shift tower and under the driver seat. steel cover plate, with flip lid/door.
With the new seat installed, the mounting bracket impedes being able to get the lid open. Will have the mechanic look at that to see how he can get it open.
One issue, the mechanic looked at the box before, and he does not have an adapter that matches the plug in this unit. I do not know what the plug looks like, so that is another task to get clarified.
I think i will need to get more information from the bus company that I purchased this from. They may have not given me all the information on this bus that i should have received.
Any other advice of things i should do or get answered, let me know.
If it's a DDEC it should shut down with no fuel and not have to rely on air pressure to shut down - FWIW
the box that is under the seat that has a flip up door is the connection for the DDEC cable connection .there is one in the driver side last bay up at the tunnel as well
dave
? if he hasn't found the port why is he looking for a cable or adapter,the DDEC ll is not hard to find a cable link for.The DDEC ll showed uses the J1708 protcol,you can buy the cable everywhere for 30 bucks
Thank you guys,
Very helpful - and also educational. The Mechanic is backed up for a couple of days, so it will be Thursday until i can get him out to help with all of this.
Thanks again
On your transmission,you should have two switches. One for the back up lights and one for the neutral switch. Simply jump them to see which one is the neutral. Whent jumped,the engine should start. If it not start,the neutral switch is not in cause. Check you FUEL switch on your secondary filter.
Quote from: niles500 on November 12, 2018, 08:25:27 PM
If it's a DDEC it should shut down with no fuel and not have to rely on air pressure to shut down - FWIW
DDEC II will shut down if you cut electrical power to it. Just turn the start batteries off, and the engine will stop because there's no power for the injectors. Simple!
John
Only if the DDEC is wired thru the battery switch...
Not a reliable procedure for a newbie that just discovered he actually has a DDEC, and can't get it to start by himself.
There is much danger to hurt oneself, when you don't know about buses and their variables.
Joe, get some experienced help onsite, the advice on these boards has always assumed a certain base knowledge, and miss oh so many basic safety steps and required checks and knowledge about the particular coach and it's unique workings.
Previous owners change things, bypass things, render protections useless, the current mechanical condition... the coach starts, won't shut off, brakes won't hold it, it's in gear, it's in neutral and it still moves, even down to where you stick your fingers and arms without knowing...
Please be careful, there is a lot to know that isn't typed on the internet.
Happy coaching!
Buswarrior
Quote from: Iceni John on November 13, 2018, 07:29:31 PM
DDEC II will shut down if you cut electrical power to it. Just turn the start batteries off, and the engine will stop because there's no power for the injectors. Simple!
John
This post is indeed interesting to say the least ,it would not surprise me if he has a Allison 741 with a shift tower instead of the pad
Very late to this thread, but popped in and saw the advice to open the master battery cut-off switch on a running engine. If you open the battery cut-off switch when the alternator is producing power, the voltage regulator loses it's reference voltage and can/will tell the alternator to produce full power by applying full voltage to the field coil. Depending on the alternator, full output could be 30 - 120 volts, which could obviously do harm to anything connected to the electrical system of the bus. This was a big issue when we were racing - we gradually switched from cars with a full loss electrical system, just a battery, where the need was for a simply battery disconnect switch, to cars that had alternators to run high current ignition systems and computers. We went to a battery disconnect with a resistor to drag down the field voltage and stall the alternator so it couldn't continue to produce voltage.
Quote from: bevans6 on November 14, 2018, 06:43:58 AM
Very late to this thread, but popped in and saw the advice to open the master battery cut-off switch on a running engine. If you open the battery cut-off switch when the alternator is producing power, the voltage regulator loses it's reference voltage and can/will tell the alternator to produce full power by applying full voltage to the field coil. Depending on the alternator, full output could be 30 - 120 volts, which could obviously do harm to anything connected to the electrical system of the bus. This was a big issue when we were racing - we gradually switched from cars with a full loss electrical system, just a battery, where the need was for a simply battery disconnect switch, to cars that had alternators to run high current ignition systems and computers. We went to a battery disconnect with a resistor to drag down the field voltage and stall the alternator so it couldn't continue to produce voltage.
He does not want to be jacking around turning a master switch off and on on a DDEC engine especially on a DDEC ll that is 12v only on a 24v system with a center tap for the 12v supply to the ECM