Non-working dome light – why does multimeter show “OL” rather than voltage?

[Gareth Randall]

I’m trying to diagnose a non-working dome light in my 2002 Ford Escape. The bulb is the cylindrical type that looks like a fuse with with terminals at either end, and it’s not blown – confirmed by both a visual and continuity check.

When I measure across the two terminals in the bulb socket, my multimeter displays “OL” rather than a DC voltage (and then drops to zero when I push the switch to turn the dome light off).

Does this indicate a short somewhere? The meter is definitely working correctly (confirmed by reading correct voltages across other components in the vehicle).

Topic

[Richard Kirshy]

If there is a short, I would think a fuse would blow.
I’d go with a possible open / break in the circuit.

[Gareth Randall]

If there’s a possible broken wire, why does the meter reading change when I push the switch to turn the light off? It reads zero volts with the switch off, OL with the switch on. Why not zero volts or OL all the time, regardless of the switch position?

I’m not trying to be argumentative BTW, just trying to learn 🙂

[Richard Kirshy]

[quote=”Dunebasher” post=204162]If there’s a possible broken wire, why does the meter reading change when I push the switch to turn the light off? It reads zero volts with the switch off, OL with the switch on. Why not zero volts or OL all the time, regardless of the switch position?

I’m not trying to be argumentative BTW, just trying to learn :)[/quote]
Could possibly be an issue with the switch itself or perhaps a control module ( if so equipped ) you will need a wiring diagram for your specific vehicle and that specific circuit .

[Author]

Replies