Troubleshooting Bendix Fast Idle/Cruise Control on 89 35FC 3208 ATAAC

[Richard Gideon]

Thanks for the reply Ralph: Early this morning I got into my "blue
box" and retrieved the booklet describing the operation and
troubleshooting the Bendix Cruise Control System (SD-10-1)and on page
15 of the booklet I found the symptoms, cause & remedy for what
appears to be ailing the CC on my FC.

V. Cruise Control System oscillates above and below the speed
setting. Will not hold a specific speed setting within plus or minus
1 mph on level highway.

Cause, CC-5 potentiometer or its wiring is defective.

Remedy. Visually inspect for broken or obviously damaged wiring to
the CC-5 potentiometer (Figure 13). Disconnect wiring connector 3 in
Figure 13 and check the resistance between the sockets shown:

1 and 3 3600-4400 ohms
2 and 3 1080-1320 ohms
1 and 2 4320-5280 ohms

If these readings are not obtained, replace the CC-5 potentiometer.

I'll post later this week, with the results of my testing. Thanks
for the guidance...I"ll dig out my digital volt/ohmeter.

Dick Gideon
Freedom Bird
1989 35FCSB
Rolla, MO

--- In WanderlodgeForum@yahoogroups.com, "Ralph L. Fullenwider"
wrote:
>
> PT cruise/air throttle/high idle
>
> Some time back, I posted to the files section, a couple of files
on how
> these systems work and inter act.
>
> As for the FC's it is a little difference because the factory <BB>
dip
> switch settings allowed the fc cruise controls to work slightly
different
> than the PT's.
>
> As for the problem in the FC, where it is on or off and no in
between, I
> would suspect the CC5 potentiometer internal of the cylinder to be
faulty.
> All this can be checked with a decent Multimeter and following the
checks
> in the Bendix manual that should be in the blue box.
>
> The only thing I have found that was done a little funky form the
factory,
> is how the clutch switch was wired up since there are no clutches
in the
> Birds and that was done with 2 solenoids in the system. I have
actually
> taken those out of the system to get my cruise working properly and
that
> was done with a pair of side cutters! One snip and you have
cruise.
> Now the problem with the break pedal not canceling the cruise is or
has
> generally been a bad set switch or corroded contacts in a
connector. And
> can usually be cleared up by cleaning the pin contacts coming from
the
> Bendix control.
>
> Remember that our Coaches put out 120 to 130 psi of air and there
is a
> regulator with the bendix set up to drop that pressure to 80 to 90
psi,
> thereby making the working difference of only a few psi
differential that
> the electronics of the bendix system reads and enacts on.
>
> >
>
> Safe travels,
>
> Ralph and Charolette Fullenwider
> 84FC35
> Duncan, Oklahoma
>