[robobot12]

Hey guys, I ran into a little problem when working on my interior the other day. I previously had several CCFL (neon) transformers hooked up in parallel to center dash cigarette lighter port, and it had worked flawlessly for over a year. I decided to clean up the wiring a little bit, so I swapped out the accessory port adaptor and created a circuit through the rear windshield wiper fuse (my car doesnt have a rear windshield wiper so I thought it would be appropriate) and grounded it to the chassis. The neons worked great for a couple hours, even brighter than before, then out of nowhere the transformers started melting and burning out... Is this caused by electrical noise or something?? I'm stumped.

 

[bluegs03]

the most likely solution to your prob is understanding that you are running to much electrical current through the wire. Thats why the lights are really bright, im pretty sure that since you dont have a rear windshield wiper you dont have a fuse for it so theres nothing to stop the massive amount of current to fry anything and everything attached to that wire.

Solution put it back to the way it is
if it aint broke dont fix it.

 

[Baker23]

^ i'm no electrician but what blue gs said makes alot of sense. i would suggest maybe wiring to a different fuse in the box maybe. one with a smaller output. imo

 

[Circuit]

Caused by too much voltage to the neons. The cig. lighter plug probably had a transformer built into it to step down the voltage. Once you removed it, you were giving the neons too much voltage (they probably require like 5 or 9 volts to run). Put the cig lighter piece back on and wire directly to that. The center "nipple" is + and use one of the two outer metal contacts for ground.

 

[robobot12]

Hmm, sounds like a possibility, only thing is that I homemade the cig adaptor out of and old one just by soldering wires to the contacts. The neons were made for computer cases and as such have step up transformers in them from 12v to ~800v thats the only reason I was confused. I suppose it is about the current passing throught the transformer then...

 

[Circuit]

The 12V input could also be a problem, since when your car is running, it runs off of the alternator and the voltage usually fluctuates between 13.7 and 14.4 V.

 

[citm2000]

There is no transformer on the cig/accessory outlet circuit. It comes straight from the ignition switch.

 

[MarkSpyder]

the most likely solution to your prob is understanding that you are running to much electrical current through the wire. Thats why the lights are really bright, im pretty sure that since you dont have a rear windshield wiper you dont have a fuse for it so theres nothing to stop the massive amount of current to fry anything and everything attached to that wire.

Solution put it back to the way it is
if it aint broke dont fix it.

I see what you are saying but I disagree. How would the circuit even have power if there was no fuse installed? The circuit would be broken as if the fuse had blown.

Robot: I assume you are talking about "cold cathodes" and not actual neons. :doh: Nevermind... I see "CCFL" now Did you put a fuse on each of the tubes? If not then that is probably why they melted. I would remove all CCFLs, install fuses on each transformer, and reinstall one CCFL kit at a time, testing each over 10mins or so to be sure they are not still melting. Seems very odd that they would melt if they had a fuse. The fuse should blow if they are receiving either too much current or too much voltage. Oh, where were the transformers mounted? Were they all packed together in a tight space or anything like that? Is there any chance that they melted due to poor ventilation as opposed to bad wiring?

 

[robobot12]

The 12V input could also be a problem, since when your car is running, it runs off of the alternator and the voltage usually fluctuates between 13.7 and 14.4 V.

Wouldnt the accessory circuit give out a fluctuating voltage like that as well??

 

[robobot12]

I see what you are saying but I disagree. How would the circuit even have power if there was no fuse installed? The circuit would be broken as if the fuse had blown.

Robot: I assume you are talking about "cold cathodes" and not actual neons. :doh: Nevermind... I see "CCFL" now Did you put a fuse on each of the tubes? If not then that is probably why they melted. I would remove all CCFLs, install fuses on each transformer, and reinstall one CCFL kit at a time, testing each over 10mins or so to be sure they are not still melting. Seems very odd that they would melt if they had a fuse. The fuse should blow if they are receiving either too much current or too much voltage. Oh, where were the transformers mounted? Were they all packed together in a tight space or anything like that? Is there any chance that they melted due to poor ventilation as opposed to bad wiring?

It wasnt the tubes that were melting, rather the transformers. According to the specifications, the transformers only draw

Current draw: 5.0mAv

which is, from a 12v source, less than half of a milliAmp. I doubt fusing them individually would make a difference.
I doubt that ventilation would have been an issue, as they were mainly in the center console and behind the radio, and the wiring was fine, it's pretty easy to make all the silver wires ground and all the copper ones 12v+ in a parallel circuit.

 

[MarkSpyder]

It wasnt the tubes that were melting, rather the transformers. According to the specifications, the transformers only draw

which is, from a 12v source, less than half of a milliAmp.

No, its 5mA, not half a mA (.5mA). How many transformers do/did you have installed?

I doubt fusing them individually would make a difference.
I doubt that ventilation would have been an issue, as they were mainly in the center console and behind the radio, and the wiring was fine, it's pretty easy to make all the silver wires ground and all the copper ones 12v+ in a parallel circuit.

Ok, so if it wasn't bad wiring and it wasn't ventilation then the answer must be cheap ass transformers. :scratch: Personally, I think you should recheck the wiring. Verify with a DVM/voltmeter that you have 12V output @ your source (rear wiper circuit). If you do then the problem is definately the way in which you wired them or faulty transformers. Nothing else would make sense. And I doubt the transformers were faulty (although they may be now) because you said they worked for a year just fine. They only acted up after you "cleaned up" the wiring so I'm 99% sure your issue comes from that. The fact that the CCFLs became brighter than normal makes me think that they are receiving too much voltage (over 12V).

Is it possible that the rear wiper runs off of 18V or 24V?? I think that would be odd but hell, its a motor so who knows. Personally, I would suggest running a dedicated 8GA wire from the battey, through the fender, and into the cabin. Use a relay to trigger that circuit on via the ignition wiring and run all your aftermarket accessories to that 8GA wire (distrib block recommmended too).

 

[tracer bullet]

There is no transformer on the cig/accessory outlet circuit. It comes straight from the ignition switch.

I think he meant (and said) the plug, on the neon wires themselves, not the circuit, if that's what you're referring to.

The neons worked great for a couple hours, even brighter than before, then out of nowhere the transformers started melting and burning out...

Agreed w/ everyone else, there's simply too much power being drawn for some reason. Something, somewhere changed without you realizing it.

Could this be as simple as a parallel / series wiring issue?

 

[citm2000]

I think he meant (and said) the plug, on the neon wires themselves, not the circuit, if that's what you're referring to.

O I C. Since he said he made it from an old one, I'd say it's a fair guess about it stepping down like Circuit said, especially if it was left over from an old radar detector or cell phone charger. Most of those step it down, sometimes way down. It would be interesting to check the input power and voltage requirements of the device from which the plug was taken.

 

[citm2000]

Could this be as simple as a parallel / series wiring issue?

Not a bad guess, either. Too many times I've seen people make mistakes wiring speakers, forgetting their high school physics lessons regarding impedances in series and parallel. Then they wonder why their amps are blown.

 

[robobot12]

Ah I think its a lost cause. I'll prob just rerun it through the Accessory port (or be smart and buy a multimeter).

O I C. Since he said he made it from an old one, I'd say it's a fair guess about it stepping down like Circuit said, especially if it was left over from an old radar detector or cell phone charger. Most of those step it down, sometimes way down. It would be interesting to check the input power and voltage requirements of the device from which the plug was taken.

No, as I said, it was made from an (I guess) an old cell charger. I gutted the circuit board inside of it, and soldered the wires coming out of it to the contacts of the accessory plug, so whatever the accessory port gives out is what the CCFL transformers were receiving. Its an anomoly, I know, since the ONLY thing I modified was the source of the power from the accessory socket to the rear windshield wiper fuse. Maybe that fuse really does give out a non standard voltage. I gotta buy myself a multimeter and sort this mess out. Thanks for your help though guys, I appreciate it :bigthumb:

 

[robobot12]

Not a bad guess, either. Too many times I've seen people make mistakes wiring speakers, forgetting their high school physics lessons regarding impedances in series and parallel. Then they wonder why their amps are blown.

They're all in parallel, that I know. Lol I'm a Computer Engineering major at the height of my E&M physics education, that was the first thing I checked.