Dometic GROUP Waeco MagicSpeed MS880 Instrucciones De Montaje página 110

Troubleshooting
The brown/white cable of the electronic module should be connected to a
brake light switch cable which is connected to either the permanent posi-
tive terminal (terminal 30) or to the ignition (terminal 15).
The brown cable should be connected to the brake light switch cable,
which connects the brake light lamp and the brake light switch. This
gives an earth signal from the brake light lamp supply cable when the
brake pedal is not applied, and a positive signal (+12 V) when the brake
pedal is applied.
The LED does not flash when an engine speed signal is received
(yellow cable)
This is how to check whether the cruise control is receiving an incorrect
engine speed signal:
Check the engine speed signal using a voltmeter or an oscilloscope.
Make sure the signal is between 6 V and 250 V and the frequency range
is between 6 Hz and 488 Hz.
Check that the yellow cable is not damaged and is properly connected to
the engine speed signal.
Test the engine speed signal on the electronic module of the cruise con-
trol:
– Connect the red cable of the voltmeter or oscilloscope to the yellow ca-
ble in the connecting plug of the electronic module.
– Connect the second cable of the voltmeter or oscilloscope to earth.
Make sure the signal at the electronic module matches that of the vehicle.
If the engine speed signal on the electronic module matches that of the vehi-
cle, the fault may be due to an incorrect PPM setting. If you chose to record
the travel speed or engine speed signal using the blue cable, the speed con-
troller does not operate using the engine speed signal (yellow cable).
To change the PPM setting, see chapter "Starting automatic mode" on
page 96
110
MagicSpeed MS880
EN