Great video. I have a two ballast set up running 4 lamps. Your video confirmed one ballast was toast. The funny part is I could have saved a ton of time by looking at the wires FIRST! The two yellow wires had melted off the insulation in several places. When I looked at the inside of the shield it was "duh!" Tar like substance directly below that ballast. But your video helped me confirm it.
When I followed this video I had different results. The old ballast had readings of 0.L for yellow, red and blue wires. When I checked continuity between red and red there was none, when I checked continuity between blue and blue there was none, when I checked continuity between yellow and yellow the multimeter beeped, showing the two yellows had a short. I later opened the ballast and the yellow wires had melted insulation resulting in a short. I then tested the new ballast. I connected the black multimeter probe to the white ballast wire and touched the six colored wires. All showed very high resistance of 400 M-ohms or more. I believe @Mikemotso [below] is correct. Each wire should show high resistance and not 0.L.
Thank you for the video. Thank you. Questions emergency battery bug eyes. ?? Why do they go bad ? Light stay on before you push the test button?? Turn off circuit the light dose not turn on on battery back up ?? Why dose it stay on when circuit back on ??
I tried your resistance test with both an analog and digital meter on the 1K, 300K and Meg scales. I tested four working, near new ballasts and they all showed resistance readings on the blue wires? Are there differences between ballast types? These are all 20+ years old, just not used. I did not want to throw them out so I tested them. By your video, they all tested bad for the blue wires, so I had to convince myself, so I wired them all into housings and they worked. Can you shed some light on this?
Before filming the video I verified by reading a few different articles about ballasts and testing them. According to what I read this is how they are tested. The only thing I could do to solve this issue is take a known good ballast and a known bad ballast test both and wire both into a fixture and test. The ballast I have in the video is unknown and un-tested.
I bought a brand new Ballast from Homedepot and tested it using this method. The blue wire showed resistance. I used it anyway. It came out good. Is this method reliable?
Nice Video! I have one light bulb that works in the fixture and the other light bulb does not work. When I switch the good bulb to the other side it works. Does that sound like a bad ballast to you?
He likely had the ballast laying around and decided to make a video about it. It wouldn't make a difference, other than to save a small amount of work removing it from the fixture. In either case it would still read a short between blue and white. As long as the power and neutral wires were disconnected, it would be the same.
by having a resistance or continuity what you are finding is that it is shorted out because there should be no connection between the white wire and any of the colored wires. continuity should only exist if the bulbs are connected and are in good condition. a good reading depending on your meter is the number 1 or OL.
thanks for the video, however is there a more direct apporach to verify the output? as in, if i hook it up to AC mains, what voltage should i be expecting on the output side? i feel like there might be a reason why the datasheets on the ballasts don't specify the output voltage, as it might be high frequency --- which multimeters can't measure, similar to electronic transformers used on LEDs, can someone give me an answer please?
The best (easy-to-follow) video on how to test a florescent light ballast!
Super helpful thank you. Quick and simple!
I will be testing my ballast and see if that is my problem.
Great video. I have a two ballast set up running 4 lamps. Your video confirmed one ballast was toast. The funny part is I could have saved a ton of time by looking at the wires FIRST! The two yellow wires had melted off the insulation in several places. When I looked at the inside of the shield it was "duh!" Tar like substance directly below that ballast. But your video helped me confirm it.
Thanx a bunch. Real clear and easy to understand...now I gotta find a replacement ballast somewhere.
When I followed this video I had different results.
The old ballast had readings of 0.L for yellow, red and blue wires. When I checked continuity between red and red there was none, when I checked continuity between blue and blue there was none, when I checked continuity between yellow and yellow the multimeter beeped, showing the two yellows had a short. I later opened the ballast and the yellow wires had melted insulation resulting in a short.
I then tested the new ballast. I connected the black multimeter probe to the white ballast wire and touched the six colored wires. All showed very high resistance of 400 M-ohms or more. I believe @Mikemotso [below] is correct. Each wire should show high resistance and not 0.L.
High resistance = OL on some older meters.. open loop.. if the resistance is that high, it means it's an open circuit
I believe he was checking for a short between white wire and the color wires. The white and the blue were shorted.
Thank you for the video. Thank you.
Questions emergency battery bug eyes. ?? Why do they go bad ? Light stay on before you push the test button?? Turn off circuit the light dose not turn on on battery back up ?? Why dose it stay on when circuit back on ??
Thank you.
helpful specially since you have same multi-meter
Do you have to find the exact same one to replace or how do you go about cross referencing to find one that works?
Thank you Sir!!! well explained.
I tried your resistance test with both an analog and digital meter on the 1K, 300K and Meg scales. I tested four working, near new ballasts and they all showed resistance readings on the blue wires? Are there differences between ballast types? These are all 20+ years old, just not used. I did not want to throw them out so I tested them. By your video, they all tested bad for the blue wires, so I had to convince myself, so I wired them all into housings and they worked. Can you shed some light on this?
Before filming the video I verified by reading a few different articles about ballasts and testing them. According to what I read this is how they are tested. The only thing I could do to solve this issue is take a known good ballast and a known bad ballast test both and wire both into a fixture and test. The ballast I have in the video is unknown and un-tested.
Can you do that test while the ballast is still in its enclosure? Of course, I would turn the power switch off first.
Does this work similarly for an electronic ballast?
Interesting video. What a nice old ballast, sad to see that it’s a goner. What did you replace it with?
It didn’t get replaced. The light was broken and ended up in the trash. I kept the ballast for video purposes.
Wow!! Narrated by the great David Lynch!
I love your video however my 8ft, 2 bulb ballast only has 4 wires, black, white ,red, and blue--is the procedure the same? Thanks again!
I would think so.
I bought a brand new Ballast from Homedepot and tested it using this method. The blue wire showed resistance. I used it anyway. It came out good. Is this method reliable?
I’m not sure how reliable it is but the way I would look at it is if your ballast works use it if not toss it.
What's your reading?
I've got red and two blue on one side, and a single black and white on the other
Nice Video! I have one light bulb that works in the fixture and the other light bulb does not work. When I switch the good bulb to the other side it works. Does that sound like a bad ballast to you?
It sounds like you have a burned out bulb
Wouldn't it make more sense to test the ballast before you take it out? Thanks!
He likely had the ballast laying around and decided to make a video about it. It wouldn't make a difference, other than to save a small amount of work removing it from the fixture. In either case it would still read a short between blue and white. As long as the power and neutral wires were disconnected, it would be the same.
You must test good ballast also to show good and bad.
Maybe a dumb question but if it display numbers that mean there is resistance or no resistance?..of there is resistance...what cause it to resist?
I am pretty sure if their is numbers that is resistance. If their is not it means it is free flowing.
If there is no reading it has infinite resistance. If there is a reading, it has continuity and it's measuring the amount of resistance.
@@markcutright9489 zero resistance, free-flow state,not infinite with no reading.
by having a resistance or continuity what you are finding is that it is shorted out because there should be no connection between the white wire and any of the colored wires. continuity should only exist if the bulbs are connected and are in good condition. a good reading depending on your meter is the number 1 or OL.
Blue red black and white. No yellow. 48" dual light fixture
All ballast have different color wires
My ballast is good, as are my lights....
Hi, you got it all wrong. bad ballast will have no reading and good ballast will have reading.
Thanks man you just brought things to light
How the hell does he get that wrong 😮
Should there be readings on all wires or just between the common (white) and the blue?
Video is right mikemotso has it wrong
They all should have open line reading....that's no resistance
If this is wrong take it down!
I don’t take videos down. There are others you can watch if you don’t like mine. Have a nice day.
thanks for the video, however is there a more direct apporach to verify the output? as in, if i hook it up to AC mains, what voltage should i be expecting on the output side? i feel like there might be a reason why the datasheets on the ballasts don't specify the output voltage, as it might be high frequency --- which multimeters can't measure, similar to electronic transformers used on LEDs, can someone give me an answer please?
I tested a bad and a good ballast connected to power. You can find the video here: th-cam.com/video/j_YUiusCRX0/w-d-xo.html.