Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Jimmyjnr on September 11, 2018, 07:52:33 pm

Title: Cruise disengagement
Post by: Jimmyjnr on September 11, 2018, 07:52:33 pm
Not thinking today and managed to have retarder engaged whilst cruise control was on . Now with retarder disengaged joy stick forward, the cruise works fine going uphill or on flats but disengages every downhill , anyone had this before
Title: Re: Cruise disengagement
Post by: AC7880 on September 11, 2018, 08:10:50 pm
Not thinking today and managed to have retarder engaged whilst cruise control was on . Now with retarder disengaged joy stick forward, the cruise works fine going uphill or on flats but disengages every downhill , anyone had this before

With retarder joystick pulled back (any position but all the way forward)  and master retarder on, as soon as throttle goes to zero, retarder engages and shuts down the cruise control.

With joystick all the way forward (but master retarder on), cruise does not shut down on our coach with zero throttle (unless on the brake pedal).

Perhaps some "grunge_ has your coach thinking the joystick is pulled back one position?
Title: Re: Cruise disengagement
Post by: Travelin' Man (RIP) on September 11, 2018, 08:34:48 pm
Jimmy, turn on the retarder with the joy stick all the way forward, like Dan said.
Title: Re: Cruise disengagement
Post by: Jimmyjnr on September 11, 2018, 08:48:27 pm
Master switch is on , joy stick forward ( off) cruise works on flat and uphill but dis engages on downhill
Title: Re: Cruise disengagement
Post by: AC7880 on September 11, 2018, 09:13:05 pm
Master switch is on , joy stick forward ( off) cruise works on flat and uphill but dis engages on downhill

The coach (Allison) "thinks" the joy stick is not all the way forward is my best guess.  Grunge, corrosion, connectors, etc?

Also possible coach thinks the brake is on?  Check with coach running and see if brake lights are on without touching the brake pedal.
Title: Re: Cruise disengagement
Post by: Pamela & Mike on September 11, 2018, 09:15:34 pm
Jimmy,

I'm not sure where your retarder interlock sending units (you may have as many as 3)  are located on an '03 but it sounds like one is stuck/bad.

The part numbers that I have are for the 4060R and I don't know if that will cross to your trans.
Mike
Title: Re: Cruise disengagement
Post by: Barry & Cindy on September 11, 2018, 11:35:38 pm
Does retard indicator light work? If not get it working.

If light comes on with downhill, retard is not off.

When retard comes on, it turns on brake light. When brake light comes on cruise will turn off. It is the brake light that kills cruise, not retard. Brake light comes on with foot brake pedal or retard active. Some can choose to disconnect the brake light with retard with a switch, so cruise will not disengage and when downhill is at bottom, cruise will re-engage throttle on the uphill.
Title: Re: Cruise disengagement
Post by: Jimmyjnr on September 12, 2018, 11:43:33 am
Just had call back from Foretravel and James confirmed everything you guys are saying, cruise thinks retarder is engaged.
His advice is go to a Cummings dealer and have them plug it in for diagnostics.
Just left coach at Temecula valley Rv for a bladder so this problem is weekend task
Title: Re: Cruise disengagement
Post by: Caflashbob on September 12, 2018, 01:26:59 pm
More useable after the repair to alter the system to have the retarder work with the cruise control.  That seems to disconnect the brake light coming on when the retarder works. 

I thought our brake light still works with the cruise and retarder but a post here says that the brake light coming on kicks off the retarder.

Not suggesting that anyone do  anything unsafe so this is just a option.

But I would not reconnect mine to the original way

Different drive to have the retarder work on cruise control.

If you want some overrun down a grade just return the wand to the off position. 

M11 remembers the last speed set which is handy regardless of if you turn the cruise off with the brake or the power on the steering wheel
Title: Re: Cruise disengagement
Post by: AC7880 on September 12, 2018, 03:04:15 pm
Our brake lights do not come on with retard active - we checked by wife following coach as I tested it out.  Retard still turns off cruise control when throttle is zero input.
Title: Re: Cruise disengagement
Post by: Travelin' Man (RIP) on September 12, 2018, 04:11:05 pm
All of the above is proof that Foretravel never built two coaches alike
The only time I ever use cruise control is in West Texas/Eastern New Mexico.
Title: Re: Cruise disengagement
Post by: Pamela & Mike on September 12, 2018, 04:14:51 pm
Our brake lights do not come on with retard active -

Dan,

That sounds like the relay that controls the brake lights that is fed from the retarder sending unit has failed.

Mike
Title: Re: Cruise disengagement
Post by: AC7880 on September 12, 2018, 06:43:16 pm
Dan,

That sounds like the relay that controls the brake lights that is fed from the retarder sending unit has failed.

Mike


I prefer no brake lights with retarder use.  When coming down a mountain with retard on, if something happens ahead and I get on the brakes hard, I want the brake lights to come on at that point to warn drivers behind me. If brake lights are already on due to retarder use, and I nail the brakes hard with a tailgater, more likely to get tail ended.

Everyone's personal preference, but I want brake lights only with active braking.
Title: Re: Cruise disengagement
Post by: Caflashbob on September 12, 2018, 09:10:48 pm
Be fun to do like 7 series BMW's do which is to have proportional brake lights depending on how hard you are on the brakes. 
Title: Re: Cruise disengagement
Post by: Barry & Cindy on September 12, 2018, 11:09:52 pm
We put a new switch on dash to allow retard to turn on brake lights.

But mostly leave switch off, so when driving Interstate with retard joy stick pulled back a little, a slight downhill will speed up coach bringing throttle to idle with a little retard (without brake lights).

When at bottom of grade, coach speed drops forcing cruise control to increase throttle.

If we drive the same way with dash switch on, the first down hill brings throttle to zero position, allowing retarder to activate, turning on brake lights and instantly killing cruise control until manually reactivated. So at bottom of grade, coach will not throttle back up.

When driving with joy stick not in off position, retard only works when throttle is in zero / idle position.  Pressing on throttle, turns retard off, even with joy stick back.