Retarder issue

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Retarder issue

July 27, 2018, 10:54:43 pm

While driving today in northwestern Colorado I had this happen a few times: When I would pull the retarder joystick a click or more to slow down on descents or curves sometimes the cruise control would not disengage, but once I tapped the brakes then the cruise would disengage and the retarder would work. It wasn't every time, most times the cruise would disengage and the retarder would slow me down.
So where should I start looking? the retarder joystick? or the cruise control?
Any thoughts?

Re: Retarder issue

Reply #1 – July 28, 2018, 12:04:38 am

I believe the problem might be "zero throttle". Retarder kicks in once it sees zero throttle.

Re: Retarder issue

Reply #2 – July 28, 2018, 01:55:15 am

Mine acts the same.

Re: Retarder issue

Reply #3 – July 28, 2018, 07:07:01 am

My understanding is that the retarder is not to be used with the cruise control (and vice versa).

Trent

Re: Retarder issue

Reply #4 – July 28, 2018, 08:50:55 am

Zero throttle? So if there is no throttle (or load) on the engine then the retarder will kick in whether cruise is on or not?
That could explain why sometimes it will kick in and other times it won't.
Yesterday's drive down CO Hwy 13 was following the Yampa river and had lots of curves with some up/downs.
I'll pay more attention on Monday when we continue.
Thanks!

Re: Retarder issue

Reply #5 – July 28, 2018, 09:28:56 am

Quote from: folivier – July 28, 2018, 08:50:55 am

Zero throttle? So if there is no throttle (or load) on the engine then the retarder will kick in whether cruise is on or not?

Yes, I think that is the case. Confused me at first as well.

Re: Retarder issue

Reply #6 – July 28, 2018, 11:01:53 am

Ours is setup so that the retarder works with the cruise control in use. Any zero throttle and the retarder comes on if powered on and the joystick off its resting position. Brake lights work when the retarder is on as far as I know also.

Being tugged back on slight downhills reminds me to move the joystick to off if I do not want to lose that particular amount of speed.

Re: Retarder issue

Reply #7 – July 28, 2018, 01:04:01 pm

There is a relay in the lower left compartment under the driver. It applies the brake lights when the retarder is activated, which turns the cruise off. Maybe the relay is going bad, or you may be having a brake light issue.
I have mine unplugged, because every burp in the road kicks the cruise off. I always make sure I apply the brakes when I am actually stopping, so those behind me see my brake lights.
Chris

Re: Retarder issue

Reply #8 – July 29, 2018, 01:04:09 pm

On my coach, the cruise control is "subservient" to any braking devise. If the retarder is in any position other than off, I cannot set the cruise. If I am in cruise and the retarder is engaged (I move the lever) with zero throttle, the cruise goes off. I prefer this as a safety measure. My cruise won't hold speed if going downhill, so I usually have it off when going through the mountains.

Re: Retarder issue

Reply #9 – July 29, 2018, 01:31:57 pm

i surely respect the safety aspect. But if you drove mine with the retarder being usable with the cruise you would have a comparison you might like.

I like that I can turn off the cruise control power on the steering wheel and the m11 retains the last speed setting in its memory and when the power is turned back on the resume function returns the coach to the previous speed without hitting the brake pedal and flashing the brake lights unnecessarily.

Going down grades with the cruise engaged and the retarder engaged allows me to control the speed with the retarder wand primarily. Off the coach can pick up some free mileage during the over run.

Retarder working with cruise helps maintain a set speed if on that may avert contact with the speed limit authorities.

Some locales in rural area have low or zero tolerance to overrunning their speed limits.

Good way to tell if the road you are on is really down hill versus guessing. Retarder tugging back is more noticeable than the throttle just returning to zero.

Much easier to drive in moderate traffic and elevation changes...

Re: Retarder issue

Reply #10 – August 01, 2018, 05:50:47 pm

Dan you're right, my retarder is working like you said, it kicks in when there is zero throttle.
Thanks!

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Retarder issue

July 27, 2018, 10:54:43 pm

Re: Retarder issue

Reply #1 – July 28, 2018, 12:04:38 am

Re: Retarder issue

Reply #2 – July 28, 2018, 01:55:15 am

Re: Retarder issue

Reply #3 – July 28, 2018, 07:07:01 am

Re: Retarder issue

Reply #4 – July 28, 2018, 08:50:55 am

Re: Retarder issue

Reply #5 – July 28, 2018, 09:28:56 am

Re: Retarder issue

Reply #6 – July 28, 2018, 11:01:53 am

Re: Retarder issue

Reply #7 – July 28, 2018, 01:04:01 pm

Re: Retarder issue

Reply #8 – July 29, 2018, 01:04:09 pm

Re: Retarder issue

Reply #9 – July 29, 2018, 01:31:57 pm

Re: Retarder issue

Reply #10 – August 01, 2018, 05:50:47 pm

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