Cruise Control Repair DDEC II

[Scott & Heather]

Ok, I'm finally getting this done. I have cruise, it's enabled in the ECM. Fast idle works properly. I have the "set/accel/resume switch and all the wires going to it. Cruise on-off switch is dead so I need to buy a new one. I'm so confused by so many things with this cruise system. Please help me sort this out all yet awesome electrical gurus.

1. Wire 558 is the wire that's supposed to go to the cruise "on/off" switch. My switch is broken toast and the wires broke off it. What switch can I buy to replace it? And where do I connect wire 558 (on off) to that switch? Does wire 558 just need 12 volts to turn cruise control on?

2. My Accell/set/resume switch is also toast with the spades actually snapped off it. Where can I buy and what do I buy to replace it. I marked my wires before removal, but in my forum research there's a lot of confusion on what switch to buy.





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[luvrbus]

Call Sam Caylor and have him ship you one,the one from my DL is different it's just a momentary bothway rocker switch I can tap it for a fast idle speed 

[Scott & Heather]

Mines momentary both ways too cliff...


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[luvrbus]

Yea but yours is a paddle not a rocker 

[Bill Gerrie]

558 is a ground NOT 12 volts.

[Scott & Heather]

Thanks Bill. I thought maybe...since the cruise control system is all just completing grounds I believe.


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[Scott & Heather]

Duh it says it on the schematic too. Wow I'm on a roll.


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[Scott & Heather]

Can anyone tell me how I can check to see if the cruise is working while parked? I don't want to have to Break camp to test drive it every time


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[lostagain]

Can you set high idle with it? Like push the accelerator to say 1200 rpm, then press the cruise set button. That is how it works on some trucks and buses I have driven.

JC

[Scott & Heather]

I am not sure if the DDEC II cruise works like that?


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[windtrader]

Scott,
Does not seem reasonable to test while parked unless you have a partial CC. For example, how can you test if it controls a set speed while parked? How can you test if the CC disables when touching the brakes? etc.

Personally, I'd make that first test flight on a very low traffic road, just in case. And be ready to shut it off if it misbehaves. Good luck

[luvrbus]

The cruise needs a sensor they pickup a signal from the speed sensor,so I don't how you could test one without the bus in motion.FWIW I never saw a cruise that would activate till it reached the xxx numbers of mph it was programed for   

[rgwilliams]

I have a DDEC 2 on my 4104/6v92.  Fast idle: transmission in neutral,park brake engaged ( mine needs air pressure to close a switch, the same one that kills the cruise control if pressure in the park brake line is 0 ie released), cruise  on, move lever to set,rpm should jump to 1000 rpm, increase rpm to desired setting with the accelerate switch.

[rgwilliams]

You can also set minimum speed for cruise to engage - mine was set for 60kmh, about 36mph. It can be set with your software to as low as 30 mph.

[rgwilliams]

Was just checking the my DDEC 2 troubleshooting manual - you can use either a vehicle speed sensor or an engine speed sensor.  You can tell what you have if you plug in your reader with ignition on, select PROM ID (MODE 3) for display and scroll through the data being displayed until you find MPH CRUISE. If the display reads N/A MPH CRUISE, you have engine speed control system. If the display reads ##MPH(## represents any 2 digits) you have vehicle speed cruise control system.