how best to find hot wire without schematic?

vintagegamer

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I'm trying to troubleshoot why the door on my Coke machine isn't getting any juice to the lights. I don't have a schematic yet, and I know where the molex connector is at that's supposed to supply the power.

I have a multimeter, and wondered if there's a way I can find the hot wire using the multimeter without killing myself? I know with a car you can touch any ground with the negative and then touch the hot with the red wire of the MM- are the same logistics applicable here?

The molex connector has approximately 10-15 wires that go to the door. Any help would be greatly appreciated.

VG
 
Back track from that Molex and find the actual power source, that way you at least have a general idea of what kind of voltage you should be expecting first. (i.e. 120v ?)

Is all the wiring in that molex the same size/quage ?
Is there a group of black wires ?
 
Back track from that Molex and find the actual power source, that way you at least have a general idea of what kind of voltage you should be expecting first. (i.e. 120v ?)

Is all the wiring in that molex the same size/quage ?
Is there a group of black wires ?

Thanks Kevin- the wires are all white, and come out of a junction box from the machine's "body" to the door. The junction box has 3 molex connectors: the bottom one which has 2 wires (I'm guessing the 'in' power), a second connector with wiring going out to the compressor, and the 3rd which has 10-15 white wires all headed for the door. They all operate the selector boxes, lights, and power for the coin mech as far as I can tell.
 
Assuming the power available at the connector is all direct curent then the same principle applies. You should be abel to find a ground and then probe each if the other wires in the harness to find one that is live. Of course, this will only tell you that power is available on that line, it doesn't tell you that it is the proper power (it could read 3 vdc when 12 vdc should be present).

Are these lights the ones for the individual selections or the lights to power up the larger display window? If you pull a bulb you can google the part number and find out at what power level it operates.
 
Are these lights the ones for the individual selections or the lights to power up the larger display window? If you pull a bulb you can google the part number and find out at what power level it operates.

All of the above- nothing in the door appears to be getting power. There is a 2 prong connector that hangs in the middle of the door's front area that powers the upper fluorescent, and it's not getting anything, nor is the wiring that goes into the fuse box that powers the selection lights.
 
"if" I understand right.. sounds like you just need to keep back tracking to find where the power cuts out at...

I remember you said the compressor powered up... where does the power coming into the machine split off and go to the lights?

I think your working on the main door lights now... and would assume those are 120...

you could always bypass and wire the door lights to a known good power source..

sounds like there may be a fuse junction box somewhere in that old machine...

trace backwards, or trace forward.. start at the plug, follow into the machine and find where it splits and supplies...

will posting pics help?
 
Sorry for the lack of pics, to get the thing out of the weather I had to put it right at the front of the garage, which is right by the door. So, I have to open the door, and open the front of the machine to get the pics, and right now it's 20 out there :(

I didn't have enough time after I picked it up to rearrange all the crap in my garage. I envy the people here who have a skating rink to both play and work on their games :(
 
well i tried sucking it up and going out there to get a quick pic, but in front of the gar door is another snow drift so i said f it for tonite. :-(
 
Here's what the inside looks like. In the bottom left hand corner is where the junction box is that the wires come from. Sorry this is not my pic.

http://s515.photobucket.com/albums/t357/ScaleBowler/?action=view&current=DSCF0751.jpg

DSCF0751.jpg
 
The wires going up into the door feed into the fuse box type thing in the middle of the below image. The wire you see off to the right with the molex connector in is the wire that goes to the fluorescent assy in the top.

DSCF0748.jpg
 
It is hard to tell from the last picture, but the red button on the side of the metal box looks like a circuit breaker. If it is, you may just need to press it to reset....

It should have some writing on it giving the rating (probably 5A or 10A) if it is a circuit breaker.

ken
 
It is hard to tell from the last picture, but the red button on the side of the metal box looks like a circuit breaker. If it is, you may just need to press it to reset....
It should have some writing on it giving the rating (probably 5A or 10A) if it is a circuit breaker.
ken
yep that it is- i pushed it 2x and nothing happened. I was going to put a wire between the connectors on the back of the breaker but wanted some opinions first.
 
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