CBE 1942

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The Italian company CBE produces cable harnesses and various control/monitoring panels, including the CBE 1942 B/C panel for Niesmann & Bischof, but also for motorhome manufacturers worldwide.

The disadvantage is that neither the motorhome manufacturer nor CBE provides circuit documents (circuit diagrams). The products are essentially a black box.

Anyone who is not willing to order and replace relatively expensive spare parts in the event of a defect will quickly despair because without the appropriate documents there is almost no chance of finding out which cable is for which function and what is switched and how.

There are now standardized cable colors and markings in vehicle construction. That was the first attempt. However, the numbering used is unfortunately outside of this standard. The cable colors are also hardly compatible with conventional labeling of the functions. Only the coding “red” (plus) and the imprint “30” (permanent plus) and “black” (ground) are consistent.

Things get colorful, in the truest sense of the word, when you look at the cable harnesses connected to the panel. In order to gain some insight into the secrets of the circuit, it is helpful to project the built-in print relays and the button symbols onto the circuit boards. In this way it is at least clear which contacts switch what (orange dots indicate ground connections).

The CBE 1942 B control panel houses the buttons and a relay:

The associated base board CBE 1942C, which is connected to two wiring harnesses, carries a whole series of relays, which are also projected onto the same here:

The Roman numerals indicate the plugs, the Arabic numerals indicate the respective contact pin. The unspecified connectors at the top right are ground connections with corresponding black cables.

Anyone who hopes that the cabling follows a certain color logic will find out by measuring that this is not the case at all. The cable colors that, according to FIAT's technical documents, are intended for the respective function according to the year of manufacture were also not used.

Since the driver's cab lighting below the original fold-down bed is replaced and switched elsewhere, the circuit was of no interest. The same applies to the switching of the pump for the engine heater, as it has its own control thanks to the installation of a diesel auxiliary heater. The entry stairs are also controlled via the smart home with an entry and exit function.

So all that remained to be deciphered were the functions of fog lights, heated mirrors and blinds on the driver and passenger sides:

The fog lights are connected to ground (black) via I3 (green), the mirror heating via II6 (green) and IV2 (green), as well as the driver's side blind via II3 (brown 67) and II5 (brown 68) and the passenger side via II2 ( violet 67) and II4 (violet 68), both moved up or down by reversing the polarity, plus leads, even when the ignition is switched off, III1 (violet).

The CBE control was therefore completely replaced by conventional switches and could be expanded, as was the CBE panel for the on-board computer, whose LCD began to give up the ghost. Its switching functions were also supported by SmartHome, which displays voltage and Tank levels through Victron Cerbo GX replaced.