Strange issue with wire/lights/

[Ryang]

Bit of an odd one

I have a 24v system (had for years) in my caravan. runs a mainly victron system except for a 24-12 step down. The 12v system runs perfectly.

However, recently Brought new hatches with inbuilt lcd ring lights, I ran a cable off the light next to it and hooked up the lights, and they won’t turn on. Assumed faulty, until I installed the next light and same thing happened.
Wire measures 11.8v at the pcb (on light) so has juice. But won’t turn on.
So today I got out the scientific power supply and hooked it up at 11.8v and the light works perfectly,

Also note - 2 hatches on 2 different lighting circuits on different fuses.

I had assumed there was a minimum voltage I wasn’t getting, now I have no idea what’s going on.

Anyone any thoughts?

P.s. lent my clamp meter to someone and never got back so can’t see amps being drawn,…

 

[Leeds]

Yank the output wires off of your 24->12 step down converter and run those directly to your new lights.

If they power up like they did with your bench meter then they probably draw more power than your converter can supply (while it's also supplying all of your other 12V needs).

If that all checks out you can either get a larger converter or get a second one that only drives your new lights. Just put the switch to it on the input side so that it doesn't run all of the time generating heat for no reason.