Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 14, 2025 ...

Retarder drops coast position

September 02, 2013, 08:08:10 pm

Driving in Cruise, all of a sudden dropped out.  The retarder came on.  Afterward, the retarder activates whenever I take my foot from the accelerator, behaving as though I had it in the first pulled back position rather than at the zero position where it is.  Ideas of what causing this?  Bad contacts?  Some interaction with the Cruise caused this?

(if you are new to retarder, when it is "on"....my term of the switch being pressed forward....you can have the joy stick in the fully forward or zero position.  The retarder should then activate only when you apply the brake, not activate because you take your foot from the accelerator.  If however you ahve the joy stick pulled back on spot, which I will call position one, it should activate when you take your foot from the accelerator.  I prefer it to "come on" or activate when I apply the brake but it id not doing that now....it activates when taking my foot from the accelerator.)

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Re: Retarder drops coast position

Reply #1 – September 02, 2013, 08:30:45 pm

Mike, does the retarder engage if you turn it off? 

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Reply #2 – September 02, 2013, 08:44:10 pm

Do you have a way to know when the cruise is ON or SET?  If not, this can be confusing without some sort of indicator light.  Our coach had no light to tell us when it was on so I set up the Silverleaf to tell me when it is ON and when I have SET the speed for cruise.  When you have the cruise SET and the retarder comes on (joy stick at a position of 1 or greater, i.e., not fully forward), the cruise goes into a suspended mode (my terminology) when you head down a hill.  You have to hit SET again to get it to take up cruise again after you push the retarder joy stick fully forward. 

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Re: Retarder drops coast position

Reply #3 – September 02, 2013, 08:47:41 pm

Anytime you have the joy stick in any postion except OFF, it will act as you say, any time you lift throttle the retarder activates, push the joy stick forward to defeat it
and back to normal.

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Re: Retarder drops coast position

Reply #4 – September 02, 2013, 09:23:25 pm

Mike,

There is a modification to the retarder switch wiring at the left dash so you can have your cake and eat it too (leave the retarder stick backward and still coast until you touch the brake pedal). It involves putting a relay in the retarder switch output line and activating it with the brake switch.

Some people like and other do not though it sure beats changing the stick position all the time.
Jim
2002 320

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Reply #5 – September 02, 2013, 09:40:19 pm

Jim, Is the mod you mentioned turn off the retarder joy stick, so retard is only with brake pedal? I have not heard of this option.

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Reply #6 – September 02, 2013, 09:47:24 pm

Jeff, if I push the rocker button to Off, the retarder does not engage.

I however I push the rocker button to On, then the retarder does engage, regardless of the position of the joy stick, if I have my foot off of the accelerator (even if the joy stick is full forward, where it should not be engaging as I have not hit the brake)

Dave, my problem is that it engages even when the joy stick is fully forward and I take my foot from the accelerator (it would normally only engage upon taking my foot from the accelerator if I had the joy stick back from fully forward position, and I have the rocker button on)

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Reply #7 – September 02, 2013, 09:54:06 pm

George, I think you may have hit on something but I am not sure how to approach this.  I wonder if in the morning since I shut down here in Vernon, Tx overnight, all may function ok?  I recall Dave M. telling me something about that I could even set a higher idle while driving....I hope I understood him right....which leads me to believe that my diddling around (technical term) with trying to set the cruise speed maybe I was not doing that but really only working the idle function.....gotta think more.

My dash light does not light up to say the Cruise is On.  But I was just moving along at 65 in cruise, it dropped out, speed fell and the retarder activated.

I am sure I am not explaining this well.  It actually happened last year, same time and hills, and MOT could not duplicate.  Then Stewart Canty at MOT said he believes that there is some connection between the Cruise function and the retarder operation, he was not sure what, and that might have been the issue....so just avoid using Cruise.  Hmmm.

will see what the morrow brings,

thanks very much to all, I need to reread each and think how it might fit together.  THANKS!

Mike

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Re: Retarder drops coast position

Reply #8 – September 02, 2013, 10:29:11 pm

Several things come to mind:

When driving along on cruise, if a slight downhill comes along, the cruise will bring the throttle to zero position because it stops accelerating, causing the retard to come on if the joy stick is not at zero position. When the retard comes on, it flashes the brake lights which turns cruise off.

I have seen the retard joy stick be in position one and not go to zero position, even though it looks to be in zero position. I found that if I firmly push the joy stick to zero/off position, and hold it there retard will be off.

A malfunctioning brake light switch will flash brake light and turn off cruise. We added a 12-volt light at foot of bed that is turned on when brake lights are on. We can see the light from front of coach and used it to help diagnose a problem.

We also added a switch to prevent retard from turning on brake lights, so when driving with cruise and joy stick active, a downhill will not turn cruise off. At bottom of incline, cruise picks back up.

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Re: Retarder drops coast position

Reply #9 – September 02, 2013, 10:40:32 pm

Great ideas!  Will check that out.

By the way Cindy, didn't you suggest one time using vegetable oil to lubricate the sewer dump valve slide gate?  Anyway, have given you credit.....used myself, worked great, and told two friends with difficult to open sewer valve slides.

Thanks for your ideas on the retarder,

mike

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Re: Retarder drops coast position

Reply #10 – September 02, 2013, 11:17:42 pm

My 2002 is close to your 2001.  I understand what you are saying.  Sounds like you are not doing anything wrong, but the retarder, as you say, seems to think the joystick is in some position other than full forward.  The rest of what you describe, dropping out of cruise, etc. is normal...when the switch is on and you are not fully off of the joystick. 

That is what I would focus on...that the joystick is somehow completing the retarder circuit when it should not.

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Reply #11 – September 03, 2013, 07:41:09 am

Hi Barry,

A simple circuit to allow coasting: use the NO pair of contacts of a 12 VDC relay wired in series with the hot side of the left dash retarder's rocker switch. The primary of the relay is activated by the NO/cold side of the brake pedal switch (so when the brake switch becomes hot/closes, the added relay closes). You simply leave the retarder rocker switch in the 'on' position all the time and it illuminates/activates only with the brake activation. If I recall correctly the relay is wired to be self-latching once activated - a connection from relay's hot output terminal to the coil terminal. I need to find the diagram I made years ago.

In this way, you may leave the swizzle stick in any rearward position and it does not engage until you touch the brake pedal. The circuit is deactivated when you touch the accelerator... and the red light goes off. You control it all with your right foot.

With this feature the retarder will not engage when coasting and yet by just touching the service brake pedal you have hands-free instant use of the pre-set retarder stick position. This does not affect the normal three-level retarder use with the service brake pedal. With this modification coasting occurs primarily with the cruise off.

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Reply #12 – September 03, 2013, 08:18:47 am

             Michael, I had the same thing happen in Louisiana after leaving Nac this year. After checking everything I could think of including pulling the control panel apart to clean contacts etc. I found the rubber boot on the base of the joystick arm was bunching up and popping the retard back to the first on position.

          Having the cruise go off and the retarder unexpectedly engage at 65 mph can really get your attention.

            Dean

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Reply #13 – September 03, 2013, 08:21:37 am

thanks Dean, glad I not the only one to have experienced this, seems crazy.  Will check the boot.  Great lead.

mike

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Reply #14 – September 03, 2013, 08:33:34 am

How do I contact forum administrators Steve and Michelle?

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Reply #15 – September 03, 2013, 09:56:59 am

I have had a couple of instances where if I engaged the cruise control the retarder would come on as soon as I took my foot off the accelerator when the joy stick was in the zero position.  This immediately put the cruise control into the suspend mode.  I have been able to overcome this each time by pulling over and shutting the engine down for a couple of minutes and restarting.  In at least one instance this happened after I had started the engine before the speedometer and tach completed their full sweep after turning the ignition on (senior moment I guess).  I suspect that all the electronics did not have sufficient time to reach their initial state before I started the engine.  There may be something else going on but it has not been a persistent problem.

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