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Topic: RE: Retarder stopped working (Read 1584 times) previous topic - next topic

RE: Retarder stopped working

Well I ran into something I have not had to fix before.
Coming up I-25 to Pueblo CO on the way to Colorado Springs I noticed my retarder light was not coming on and then I realized the retarder was not coming on as I am coming down the hill.
I checked the wiring diagram and saw no fuses or circuit breakers.
I pulled the joystick connection out & back in and the light came on briefly so I know the bulb is good.
I pulled the kick plate by the brake peddle to look for these 3 pressure switches but cannot see them.
Anyone know what the pressure switches look like or where the resistence module is located.
What I else I should be looking for as the culprit?
I don't like driving these mountains without that retarder :o ???

Re: RE: Retarder stopped working

Reply #1 –
Barry,

Don't know where the pressure switches are either, but I would try pulling the panel with the joystick and unplugging/replugging the Allison control.  Did the trans throw a code? 

Re: RE: Retarder stopped working

Reply #3 –
Quote
Here's a post I found for similar symptoms, Also has Allison phone number for assistance

I talked to Allison Service 800 252 5283 & he suggested since I dont have the diagnostic software to just take it to Denver (Commerce City)  Allison and let them diagnose it while driving it with their software
So off to Denver after the 4 corners Rally.

Re: RE: Retarder stopped working

Reply #4 –
Barry,
I don't know about your '03 but my '98 retarder pressure switches are in the street side, forward most compartment, through-mounted in the forward sheet-metal bulkhead, high and to the left as you face into the compartment, just forward of my generator compartment release cable handle.  I know that your compartment has genset cooling radiator, fan and other components, but your switches may be in that vicinity. 
But aren't the three pressure switches for the three stages of retardation with increasing air brake pressure?  Do you get any retard light on with the retard switch on and varying degrees of brake pedal pressure?  It sounds more like the joy switch connector to the joy stick resistance module, especially where you got the light to flicker when you pulled the joy stick connector.  I haven't heard of a retarder resistance module going bad.  A loose wire or connector would seem much more likely.
As I recall, my resistance modules just lay in the mass of wires under the joy stick/switch panel removable faceplate.
Worth a try.
Neal

Re: RE: Retarder stopped working

Reply #5 –
Quote
I don't know about your '03 but my '98 retarder pressure switches are in the street side, forward most compartment, through-mounted in the forward sheet-metal bulkhead, high and to the left as you face into the compartment, just forward of my generator compartment release cable handle.  I know that your compartment has genset cooling radiator, fan and other components, but your switches may be in that vicinity.
Thanks Neal, I found them in that compartment but unreachable for me.
Mark Harvey had told me they were behind the kick plate by the brake pedal.
Looking in that compartment they are all the way in the back (arms Length) to the top left.
Quote
Do you get any retard light on with the retard switch on and varying degrees of brake pedal pressure?  It sounds more like the joy switch connector to the joy stick resistance module, especially where you got the light to flicker when you pulled the joy stick connector.  I haven't heard of a retarder resistance module going bad.  A loose wire or connector would seem much more likely.
I get no retard light with brake pressure which is what I noticed 1st that I had a problem.
Quote
As I recall, my resistance modules just lay in the mass of wires under the joy stick/switch panel removable faceplate.
I can see the "split plastic loom" from the joystick connector going forward but do not see or feel anything as I put my hand in. So it may be closer to the front.
That info is good for an ATA BOY Karma  8)

Thanks to Barry Leavitt for reminding me that I needed to hit the arrows TWICE to read the diagnostic codes. He gets an ATA BOY to.  8)
I came up with:
  D1 46 26  &  D2 35 00
   
   46 26 - N & H Solenoid Circuit Over Currents
   
Solenoid Overcurrent
   1. Check:
      a. Main transmission connector is tight, clean, and undamaged.
      b. ECU connectors are tight, clean; and undamaged.
      c. Wiring harnesshas no opens, shorts between wires, or shorts to ground.
   2. Replace ECU.


   35 00 - Power Interruption

Hardware!Software Not Compatible
   1. Check that wiring harness has no opens, shorts between wires, or shorts to ground.
   2. If able, recalibrate ECU, if not, replace ECU.

Re: RE: Retarder stopped working

Reply #6 –
Hi Barry,
Glad I helped a little bit, but you still have the problem.  Of course Allison can easily diagnose it to the precise location, BUT,
I still like my first impression...........that you have a single ECU wire or connector, near the Joy Stick, that is making a poor connection.
Your Diagnostic codes point to poor connections (and the Allison ECU..........which is very low probability in comparison).
It looks like you have three ECU retarder connectors somewhere under your "Joy Stick, Accessory Switches, Shift Pad Panel".  If your panel faceplate is removeable like mine, I'd lift it out enough to find those connectors, as the highest probability culprits.  You got the bulb to flicker before, so I'd still put my money there.
If you can get some Corrosion -X on the Brake Switch Pressure Switch terminals, I'd also do that.  In order for my Allison 3060R to function properly, the ECU must see a current path all the way from the ECU, through the shift pad, through those brake switch terminals and through the brake light bulb  filaments to ground, in order to be happy.  For me, if one of those terminal connections is poor or bad, I can end up in "Limp Home Mode...........@1000 RPM Max" because the Allison thinks that I do not have brakes.  Maybe it also has some form of Retarder control function.  I don't know for the larger engines and transmissions.
Of course, the other important connector (potential culprit) is at the transmission itself.  Less likely but a possibility.
Good Luck, Barry.
Neal

Re: RE: Retarder stopped working

Reply #7 –
I am sure you checked this, but have to ask anyway:  have you checked for power on both sides of the retarder rocker switch?
Bob

Re: RE: Retarder stopped working

Reply #8 –
Quote
I am sure you checked this, but have to ask anyway:  have you checked for power on both sides of the retarder rocker switch?
I disconnected the cable from rocker switch & I read continuity across the switch when it was on. The rocker switch is good.

Re: RE: Retarder stopped working

Reply #9 –
brake light bulbs???

Re: RE: Retarder stopped working

Reply #10 –
And, if all else fails, or perhaps before trying anything else, consider applying Percussive Maintenance. 

From my USAF (Ret) brother:  "PERCUSSIVE MAINTENANCE - The fine art of whacking the crap out of a $200,000 inertial navigation unit to get it to work again."

Re: RE: Retarder stopped working

Reply #11 –
Quote from: sgkarnes –
brake light bulbs???
Ooooooooooooops!
Thank you , Gary
I've just had another senior moment and your question about the brake light bulbs set me straight.
The "Limp Home...........@1000RPM" mode, if I have no brake light filaments to ground, is a King Cruise Throttle Control issue.  It's not an Allison ECU issue.
See Bill W's (and my) notes in Barry's "Beam Alarm Notes".  Quoting Bill W:
"The King cruise control relies on the brake light circuit to know when coach brakes are applied, so it can safely turn off the cruise control when brakes are applied. To be sure the brake light circuit can be 'seen' by the cruise / throttle control (which is the same circuit board) the controller must see a resistance through the brake light bulb to ground. If the brakes lights appear to be burned out or otherwise malfunctioning the King Control will only allow about 5 to 10 MPH of throttle control."
Sorry for the senior moment.  Best of intentions, just one of my ordinary, every-day, mind f--ts!!
Neal

Re: RE: Retarder stopped working

Reply #12 –
Quote
It looks like you have three ECU retarder connectors somewhere under your "Joy Stick, Accessory Switches, Shift Pad Panel".  If your panel faceplate is removable like mine, I'd lift it out enough to find those connectors, as the highest probability culprits.  You got the bulb to flicker before, so I'd still put my money there.
I removed the wiring plug from the joystick and cleaned all the terminals and plugged it back in.
I am back in action.
Driving to Colorado springs the retarder appears to be working , hopefully permanently.
Maybe saved a trip to Denver  ;D :)) :)
Case Closed. ::)


Re: RE: Retarder stopped working

Reply #13 –
Quote from: Barry Beam –
Quote
It looks like you have three ECU retarder connectors somewhere under your "Joy Stick, Accessory Switches, Shift Pad Panel".  If your panel faceplate is removable like mine, I'd lift it out enough to find those connectors, as the highest probability culprits.  You got the bulb to flicker before, so I'd still put my money there.
I removed the wiring plug from the joystick and cleaned all the terminals and plugged it back in.
I am back in action.
Driving to Colorado springs the retarder appears to be working , hopefully permanently.
Maybe saved a trip to Denver  ;D :)) :)
Case Closed. ::)
Barry,
Good news, and great analysis from the group & execution on your part.  Glad you were able to persist and solve the problem.  It never ceases to amaze me how many electrical connections there are that can cause problems that seemingly look to be huge problems at first glance.

Re: RE: Retarder stopped working

Reply #14 –
Barry,

Your last post is now in my Foretravel Tips file.  This is something even I can do.  Looks like you won't be giving any money to Allison in Colorado any money.  Bad for them.  good for you.

Re: RE: Retarder stopped working

Reply #15 –
Quote
Looks like you won't be giving any money to Allison in Colorado any money.
I feel real bad about that  :P
And I dont have to leave this rally to go to Denver.
You are so close, you should have come to Colorado Springs to the rally.
you are going to miss all the fun.  ???

Re: RE: Retarder stopped working

Reply #16 –
The experience brings to mind an experience in our previous 37' DP coach.

The coach did not have the propane capacity to heat the coach for more than about 2 1/2 days in cold conditions. We were in Montana and the blizzards started rolling through. We fled southward because we feared getting snowed in and freezing up the water systems. During driving on snowy roads, the Allison transmission went into "limp" mode and would not shift above 2nd gear. We found a highway maintenance lot along the road in Kansas where we holed up for the night.

We called Coach-Net for help. They diagnosed the transmissions code as a lost speed sensor. They arranged a tow and a shop appointment for the next day. In the bright sunshine of the next morning, I crawled under the coach and found the wire that had been pulled from the transmission by the weight of accumulated ice. After applying some heat from a hair dryer, I removed the ice from the wires and was able to reconnect the warm, pliable rubber plug and socket. All worked well.

We canceled the tow before it left the shop and were on our way. As soon as we arrived home, I started looked for a coach that could survive a few days of blizzard conditions without having to move. We now own a U295 that carries 42 gallons of propane, a strong diesel generator, lots of fuel, and a well insulated basement.

Be prepared for conditions, and check the wiring if anything gets flaky. It's annoying if when something quits working, but can be satisfying if you can fix it yourself with a little bit of help from your friends.

Re: RE: Retarder stopped working

Reply #17 –
Quote
It's annoying if when something quits working, but can be satisfying if you can fix it yourself with a little bit of help from your friends.
Ahhhh friends. Its nice to have all the accumulated knowledge in one place. 8)
We are sitting here talking about horror stories some have had with service techs.
Joe Sharp M/C # 4053 the 10th oldest Motorcade member is telling us some of his issues he had with 4 service locations here in Colorado Springs. You can't make this stuff up.

Re: RE: Retarder stopped working

Reply #18 –
Hey Barry!
You Da Man! 
You sure make the FoFum TEAM look GOOD!
Glad things are looking up and I'd put money on the retarder problem staying fixed.
ENJOY the Rally!
Neal

Re: RE: Retarder stopped working

Reply #19 –
Quote
Glad things are looking up and I'd put money on the retarder problem staying fixed.
It is good to be reminded to check the easy stuff 1st.
Thanks for your logical suggestions.
That connection looked so tight you would never think there could be resistance in there.
Shows to go ya  ::)