Test Rig for Auto Lights

[Lonnie-S]

I'm going to start setting up some lights, including some LED lights, in a day or two. I'd like to have a test rig (12V source) that's safe to use to test the lights as they're installed. I do have my old donor battery, but I'm hesitant to use it as a direct source. Any suggestions?

I'm open to buying or building one.

Cheers,

[horchoha]

I've used a 12V car battery many times for testing lights.
If you want, install a 10-20A inline fuse or circuit breaker on the +ve lead wire. For that matter you could also install a toggle switch.

When I worked in the gas company automotive shop, we had a wooden box set up with a car battery that had a circuit breaker and toggle switch. It had RCA style jacks that you plugged the +ve and -ve leads into.

[toylocost]

For car audio testing I’ve always used a battery with a charger on it at the same time to hold voltage between 12 and 14. For longer term testing you can get decently large 12v power supplies on amazon. Just watch the amperage draw on those lights. But you should be fine with just a battery and charger. Use a fuse if you feel safer that way.

[Bent Wrench]

Instead of a fuse you can use a headlight in series.
It will light if there is a short, glow dimly for higher loads.

[Miatav8,MstrASE,A&P,F]

When I was in aircraft mech school, I used to connect jumper cables to a battery and a starter than drag the ground down the case and watch the airframers run for cover. Fine wire to a classmates metal frame chair (rivetted seat area) and the other end to a magneto I would spin ocassionally. Charge large capacitors and toss them to class mates. Electricity never hurt anybody, right?

[berg]

Do yourself a favor and go out and buy a Power Probe tester. https://www.powerprobe.com/ I bought one couple of years ago and last year upgraded to the gen3. Wasn't sure I'd use it that much but it was on sale. Now it is my go to tool for anything electrical. Can't say enough good about it.

[Lonnie-S]

I've used a 12V car battery many times for testing lights.
If you want, install a 10-20A inline fuse or circuit breaker on the +ve lead wire. For that matter you could also install a toggle switch.

When I worked in the gas company automotive shop, we had a wooden box set up with a car battery that had a circuit breaker and toggle switch. It had RCA style jacks that you plugged the +ve and -ve leads into.

That sounds like a pretty simple solution. What type of circuit breaker did you use?

Cheers,

[Lonnie-S]

@toylocost
@Bent Wrench
Perry's solution uses what I have except for the circuit breaker and toggle switch. I have some old RCA jacks in my toolbox and a toggle switch is pretty cheap.

@MV8
What a naughty boy you were. And yes, electricity will definitely hurt you. I started learning about cars on old Ford flatheads. You know, the ones with the unguarded spark plug wires. I had many encounters with those under power.

Flathead spark plug wires.jpg

@berg
That's a nice tool, but $400 is a little rich for my blood. Thank you, though.

Cheers,

[horchoha]

For the test box it was a breaker like this which is mountable to the box.
https://www.delcity.net/store/12V-Auto-Reset-Circuit-Breakers/p_198669.h_198846

[Lonnie-S]

@horchoha
Thank you, Perry.