I am having an odd problem with my gauges cooperating...
my wiring:
I have a relay that turns on when the ignition is on and it send direct power to the gauges from 1 of the main power wires in the car and ground comes from the chassis...
all gauges share the same power wire and chassis ground, voltage at the battery with the car running is 14.2 and voltage at gauges is around 14.18
it seems my Cyberdyne Voltage gauge works fine ONLY when the AEM's wideband sensor is NOT connected, but the AEM gauge can be connected... if I connect the sensor, the cyberdyne voltage gauge reads LOW or 10.1 volts instead of normal.
If I connect my DMM it reads the voltage with no problems (with the AEM sensor hooked up or not)
I am wondering if there is some sort of signal feedback comming off the AEM gauge with the sensor hooked up
I am up for suggestions
I would first verify that you have a solid ground. Plugging the sensor in shouldn't cause the voltage to drop, but could create a little feedback as the heater in the O2 sensor is typically PWM (turns on and off really fast which can create noise).
What I would do is connect the O2 sensor and get the AEM working. Then, disconnect the power and ground from the voltage gauge and try getting power for it somewhere else. (like the coil of the relay instead of the contacts). See if that fixes the voltage reading.
I would think though, if you have a solid voltage and a solid ground both guages should work with no conflicts.
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Kevin Pierson