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In automotive the switch is (sometimes) After the load (bulb) so the wire into the bulb and from the bulb is always Hot with respect to ground.
In our homes the line is only Hot up to the switch, and from the switch to the load to ground is (well) switched.
One way to find out is to Ground the 'far' side of the load, if you blow the fuse then its the 'source=Batt' side of the load, if the load 'works' then you know that the path to ground has the switch in it. Unless of course there is a supply side switch which happens to be on already.
Another thought is that you might have a High Resistance Ground and or Source, i.e. when you switch on the bulb, current is flowing, but not sufficiently to enable the bulb to reach incandescence. Think of a flashlight, when it gets dim or doesn't light you smack it, well that giggles the batteries and cleans the connections between the batteries. Granted the car is 12 volt, but still loose or corroded connections are significant to the flow of current.
The seasoned H-D Tech's were discovering a lot about my suite of sweet tools.
It was a good deal I negotiated with then: "Trade tools for knowledge."
The were always wanting to borrow my stuff, and only occasionally had I need to borrow their tools which I then went out and bought to add to my collection.
In return, they didn't make me struggle and "Look it up" when I encountered something that I was unacquainted with.
I'm not sure I follow what you're saying. I don't know electrical worth a poo though.
Just test from the ground part of the socket to chassis ground.
If you do have continuity then it's some other issue, but I think it's a disconnected, or bad, ground.
Just test from the ground part of the socket to chassis ground.
If you do have continuity then it's some other issue, but I think it's a disconnected, or bad, ground.
Ok. That explains it a little better. I'm sure Dave's explanation was more technically thorough, but he might as well have been speaking Swahili.