The best electrical test ever

[decca]

I've had this very 12v bulb on these 'red and black wires for as long as i can remember. They have got me out of many an electrical pickle by showing if a circuit is ok or not much easier than a meter, it either lights or it doesn't.

Just want to say thanks to Mr Swan.

 

[piman]

Hello Decca,

very true, a meter used wrongly can give false voltage readings. A high resistance joint will give full voltage when measured if the circuit is not switched on. A bulb loads the circuit whether it is on or not.

Alec

 

[Ruffian]

And a bulb on a wire can help detect shorted out wiring far easier than other methods,

(If used correctly)

 

[daleyd]

The inbuilt hi tech diagnostics for a 4.5 mk8 gun loading system was....

...A curly cord with a “pen” on the end which was connected to a lamp.

 

[8ob]

The most basic of tools are always the best Power probes are only a bulb on a stick with a switch but they are my go to for chasing smoke feeds and leaks. Rocker switch can supply or detect 6-36v of indicated live or neutral, cant beat them for chasing wiring problems around trailers or trucks.

 

[merryman]

Yes, 12v test lamp is my go to tool for checking starter circuits on Quads, you can tell if it is starter motor or solenoid (separate on ATVs). Shorting the solenoid as a test only works if the fault isn't intermittent, a test lamp between starter live and earth tells you which it is. Also once fitted a new alternator stator to a Honda 500, sod of a job as the swinging arm has to come off to get at it, then found it still didn't charge. Testing with a lamp gave a dim light at the voltage regulator (separate again) to battery positive wire, found a pinhole in the insulation and, when opened up, about 1/4" of verdigris where the copper wire had been. Voltmeter had shown 12v when I originally tested it before fitting the stator.

 

[RWD3M]

Agreed, but I've had to double up recently after buying a 1936 Morris with 6volt electrics and forever getting them confused!

Note to self - put a bl00dy label on them!