Check the ground wire within the circuit. You would never have any voltage at the switch it is just opening the hot.
Px Running Cable To Lighting Fixtures Fx Luminaire
Low voltage reading at light switch. What the p0851 code means. The code p0851 indicates that the voltage reading from the parkneutral switch input circuit was too low compared to the manufacturers specifications for the current driving conditions. When he measured the voltage from the source it only read 105 volts on the meter. Thats lower than our system voltage at about 125 but not low enough to explain the severe dim out. He installed the light turned the power on but the light did not work. A low voltage condition such as this is typically an indication that the circuit ground wire may not be properly bonded at the panel or the ground wire may not be attached or properly spliced at a connection point within the circuit.
Btw if there is power in the ceiling. A multimeter can let you know if the range is less than 120 which is the expected voltage in a homes electric wall outlet. Experts on old stuff help then the switched power goes back to the fixture but if the switch is not there no power is ever at the fixture. There is no neutral for reference and in this old thing maybe no ground. The reading was 105volts on the meter again. If the switch is off and the other measurements might be phantom voltage 20 100 volts.
Tighten the screws that hold these wires in place. Once you discover a low voltage electrical outlet unscrew the plate and locate the ground neutral and hot voltage wires. These relays in turn were controlled by small light switches operating at a low voltage comparable to that of a doorbell. The switch leg will meausre zero hot to neutral if the switch is on. He installed the switch and measured the voltage at the ceiling box where the light would be installed. This code is only found in vehicles with both automatic transmissions and four wheel drive capability.
The voltage you meter at the low beam lug as it turns out is about 11 volts. This might fix your issue. Inspired by industrial systems that relied on relay switches to control motors lights and other industrial equipment vintage remote control wiring systems used relays to switch a current.
Gallery of Low Voltage Reading At Light Switch
/cdn.vox-cdn.com/uploads/chorus_asset/file/19494742/wire_illo.jpg)
