Brake light voltage readings.

[Z71Sierra]

Trying to determine why a guy at work had no brake lights. What readings should he get when testing the socket?

1995 Silverado

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[twomanymontes]

Should have 12 volts into the switch, 0 volts on the wire coming out until the brake is depressed, then 12 volts.

What year? I can try and look up wire colors if you need them

 

[Ruger_556]

With the bulb in the socket it should be 12v on the hot wire. If not then the problem is the switch or the wiring up to the light. If you have 12v on the hot wire and the light isn't on the bulb is burned out or there's a bad ground. If the bulb is burned out there will be 12v on the hot post and zero on the neg. If it's a bad ground there will be 12v on both posts.