2001 e350 overhead light question

[Smileycatcat]

Hi all, I posted here about the one light not working. I've taken apart both not working and working light fixtures. Working one has 13volts on the black leads. The non-working one has 0. Would it be safe to assume the on/off switch is the problem?
Thanks, 2001 ford e350 high top

[BrianW]

I’d unscrew it and pull it down and test the actual lead wires before the fixture to see if you’re getting hot to the fixture. If so, then you can troubleshoot the fixture itself.

[N147JK]

Test the voltage on the line prior to then after the switch. But it's not likely the switch - you will probably have to work on the components on that pcb (assuming both bulbs aren't burned out).

[1der]

Remember it could be a failed/disconnected ground wire. You may have 13v on the black wire but no ground connection on the other wire. That would read zero on the meter.

[basssears]

Is that a fluorescent fixture or did you convert it to LED? If it's fluorescent could be bad ballast but it looks like maybe you've converted it. -- Bass