By Marc Markell

The Veglia instrument cluster was removed and setup on a workbench with a variable power supply. The voltage applied was varied to get the Voltage Meter reading positions, then the voltage was fixed at 14.5 volts to simulate normal alternator operation and a variable resistor was applied between the various other meters and ground to determine the relationship of resistance to meter position.

Note that these meters use a dual coil movement and MUST have power applied to the entire cluster to read correctly.

Note also that these readings are in terms of needle position, not PSI or Degrees as that is a function of the senders attached to the block. An oil sensor is available for instance that would have full-scale equal to 80 PSI, and a different part number will have full-scale equal to 100 PSI. The oil and temperature guages use senders compatible with Stewart-Warner, Datcon and ISSPRO senders in that they have decreasing resistance with increasing pressure. The fuel guage uses senders similar to VDO guages in that the resistance goes up with increasing readings. The Veglia cluster has no numbers implying either pressure or temperature, so the senders are not absolutely one set of part numbers.

This project was begun in a quest for a replacement oil sender for an S1 Esprit and the sender noted is presently on order for a trial. It does use an English rather than a Metric thread, but an S1 uses a tube connection anyway and adapters are available. In my case I’m going to replace the engine plate that has the oil pressure spigot with a billet plate and a different position for the spigot to allow me to mount the sender directly on the block using 1/8 NPT threads. (The starter interferes on a normal 907 engine). I’ll try to find equivalent temperature and fuel senders next.

Summary of Veglia requirements:

Oil pressure:

Full scale 68 ohms to ground.

Top of red area 360 ohms

Zero PSI 470 ohms

(Reverse scale due to meter mounting upside down)

Probable replacement sender: Datcon #0250400

1/8 NPT thread

240 Ohm at 0 PSI, 33 Ohm at 80 PSI

May need to add a resistor for scaling.

Temperature:

Bottom of red area 19.7 ohms

Bottom of scale 198 ohms

Fuel

Full 44.5 ohms

½ 134.5 ohms

Top of red area 276 ohms

Empty 376 ohms

Voltage

Left end 11.22 Volts

First tick 12 Volts

Second tick 14.6 Volts

Right end 17.7 Volts