electrical question-lights

[Foisy]

I have additional aftermarket lights on top of my cab. Two facing front and two facing back. Both are wired the same way through an after market electical panel in the roof on the cab where a stereo sits and a 12 volt outlet. Two toggle switches control each set of lights. The two lights facing front do not work. Everything else works.

I put a meter on the wire right at the light and it appears to have 12 volts across the single wire on the bulb to ground. The bulbs don't appear burnt out.

Any thoughts on what else I could try?

 

[traildust]

You have 12v on the power wire to the lights. When you are checking the ground are checking what the fixtures are actually using for there ground?

Scott

 

[Foisy]

I used a spot on the cab. I will try the spot in the light fixture that it uses for the ground. I will report back.

 

[B7100]

I have additional aftermarket lights on top of my cab. Two facing front and two facing back. Both are wired the same way through an after market electical panel in the roof on the cab where a stereo sits and a 12 volt outlet. Two toggle switches control each set of lights. The two lights facing front do not work. Everything else works.

I put a meter on the wire right at the light and it appears to have 12 volts across the single wire on the bulb to ground. The bulbs don't appear burnt out.

Any thoughts on what else I could try?

Is the bulb earthed via contact with the bulb holder and not a separate earth contct in the bottom of the holder? if so put your meter in ohms or continuity mode and test between the metal side of the bulb and its contact..there should be continuity and shows the bulb it working.If it is ok,put it in the holder and check for continuity between the metal side of the bulb and an earth point on the tractor frame to see if there is continuity..if yes then it should work,if not and you definately have power to the contact in the bottom of the holder them look for an earthing fault between the holder and tractor frame.

good luck
Dave

 

[Foisy]

Thanks for the advice. Everything I tried was checking out so I connected the removed bulb to a spare battery and found out I had a burnt bulb. I had already tried a replacement bulb so this wasn't sitting well with my ego. Connected the replacement bulb to the battery and (ready for this) the replacement bulb was also bad. Ran down to the TSC store and grabed two new bulbs and I now have lights. I don't know why the previous owner let two lights burn out without replacing them, but after a frustrating ordeal, my new tractor has lights again. I really hate electrical problems.

 

[traildust]

Thanks for the advice. Everything I tried was checking out so I connected the removed bulb to a spare battery and found out I had a burnt bulb. I had already tried a replacement bulb so this wasn't sitting well with my ego. Connected the replacement bulb to the battery and (ready for this) the replacement bulb was also bad. Ran down to the TSC store and grabed two new bulbs and I now have lights. I don't know why the previous owner let two lights burn out without replacing them, but after a frustrating ordeal, my new tractor has lights again. I really hate electrical problems.

Don't worry about it, it's all good. I happen to LOVE electrical issues and shooting wires is what I do best.

Some things form my experiance. Using a meter to ohm a bulb can be misslieading. If it's an incandescent bulb and the filament isn't quite gone it will check good with a meter, but it will not illuminate with power on.

The same goes for ringing out a wire run. Let's say, in your case, you had the 12v on your hot wire AND you had a confimed good bulb because you swapped to another postion an it worked. But it refuses to illuminate in the forward position. You have confrimed the voltage good at the bulb pickup and its ground as well. Now switch the meter to ohms and ring the wire run. As you would expect it checks good with low to no resistance.

The problem could be the wire. If the wire has, say 20 strands, and has been damaged so that only one strand is left then the meter will always find the correct voltage and it will show good resistance. Meters can be deceiving since they will get coninuity through a nats ass. But you try and put a load on there and there just isn't enough wire remainging to pass the needed amperage.

This is when a megger comes in hand. It shoots a high voltage through the line and will find any problems in the wire. If you had a wire with one strand it would find it and probably even burn it out handing you your problem area.
Caution with meggers: Always insure that both ends of the wire are disconnect or you will fry what's at the other end. And NEVE EVER touch the leads with your hands while activating the megger. I have as a bet and will not be doing that again

Enough for now


Scott

 

[Foisy]

This is when a megger comes in hand. It shoots a high voltage through the line and will find any problems in the wire. If you had a wire with one strand it would find it and probably even burn it out handing you your problem area.
Caution with meggers: Always insure that both ends of the wire are disconnect or you will fry what's at the other end. And NEVE EVER touch the leads with your hands while activating the megger. I have as a bet and will not be doing that again

Enough for now


Scott

I've never heard of a megger? Can you tell me more? I'm assuming it has a power supply or something.

 

[traildust]

I've never heard of a megger? Can you tell me more? I'm assuming it has a power supply or something.

Older meggers used to be kinda big and had a hand crank to spool it up. Now it's not uncommon to find one of those as a back up. Most line use are self powered from something as small as a 9v battery. BUT DO NOT underestimate this little guy as it has a capacitor that trunks the juice and amplifies it. When you hit the trigger it shoes no mercy. I have been shocked by the 9v supply because I was making fun of the owner (mistake) it was pretty painful to say the least.
Large industrial kind may be as big as a suitcase that requires power from another source, like 110 or even 220.

Meggers come in all kinds of sizes and styles. Now, with technology improvments, meggers are not always a stand alone tool. One of my favorites at work is made by Fluke, it's everything in one: Volt/ohm meter and megger.
It is just barely bigger than an average Fluke meter.
I believe the running price for this unit is about $600.00. I will never own something that nice but lower cost units are available.

There are some pictures a fellow made and posted on line. It's a regular piece of notebook paper with pencil marking in the lower section. He connected one lead to one side and the second lead to the opposite side. It shows tthe power of a megger taking care of a short.

Now, meggers will shoot a variable voltage that you set it at. You wouldn't want to send a test supply of 2,000v through a low voltage line so there are meggers for low end voltage as well.

Here is the link to that fellow pictures, really cool!


Scott

 

[Foisy]

Hmmm, looks like another must have tool. Thanks for the information. I googled it and found plenty on it. The link you sent is pretty cool but shows that this tool is to be used with caution. I can envision my wires lighting up like that paper.

Could be a neat way to protect my metal beer cooler from leaches!

 

[traildust]

Could be a neat way to protect my metal beer cooler from leaches!

HA HA HA! That is FUNNY

I never thought about it but I personally garuntee nobody will ever snatch a beer again!

Used properly your wires will never end up like that paper. It's just an over exaggerated example and having fun at the same time.



Scott

 

[Joshua Zahn]

Older meggers used to be kinda big and had a hand crank to spool it up.

Scott

I'm still using my Dad's old hand crank at work. It's about 6"x8". A baby. You can sometimes pick em up cheap (the old ones) on fleabay.

 

[traildust]

I'm still using my Dad's old hand crank at work. It's about 6"x8". A baby. You can sometimes pick em up cheap (the old ones) on fleabay.

Hey Josh,
I always think that is the coolest thing when good tools get handed down and stay in use.
You will always take care of it and it's also more than just a tool.

Take care,
Scott