Question on wiring system

[napapacoda]

Idiot me took off the 4 gauge wire from the battery to the capacitor and now doesn't know which one is positive and which one is negative (used same color wire for both). So I tried testing it with a multimeter (it took me a while to find one, but i used a ghetto one that in reality didnt work that well). To make a long story short, I hooked up my system thinking I had the right wires on, but when I put the power from the battery into the fuse holder in the front, it made a spark and cracked the fuse. I am guessing that I reversed the power and hte ground at the distribution block. It was too cold and dark to do a switch to see if that would fix it, but I was wondering if anyone had any ideas on whether i fucked my capacitor or not. I'm guessing its the fact that hte power saw the ground on the capacitor that made the fuse blow since my car wasnt on and the remote turn on wires therefore did not turn on any amps or actually turn on the capacitor, but the cap was already charged. Any chance the fuse saved the day from my car audio equipment being damaged?

[ta2dSi]

if the fuse was between the capacitor and the power supply, then you should be good. The best way to check the capacitor, is to look up capacitive impedance, and you will find the equaltion to figure out the actual ohmic value of the cap.. If you measure it and it is the same, then you should be ok. If you read less or more, like an open, or a short, then the capacitor might be lost....

The easiest way to check which one was ground and the which one was 12V, was to check them with the multimeter, and if you read -12V then the end touching the red probe would be the ground

[napapacoda]

THanks for letting me know. I tried touching a ground point on my car and then touching both wires to see which one looked like it made a connection. But this multimeter I used was a pos from probbaly the 70's or 80s. I'll try the multimeter I just found that actually works right when it warms up. If the cap is fucked, it sucks but no big loss, I have 2 spare ones just sitting around.

btw - paxie, have any input on this?

[napapacoda]

Can anyone think of what might be wrong. Today I went to switch waht I thought was wrong (I thought the positive and negative power wires going into the distribution blocks were reversed and that is why when i touched the wire from the battery to the fuse in the front, it sparked and the fuse blew. So I switched the wires without thinking about using a multimeter because I thought it had to be the problem. I have a brand new fuse in there, but still after the switch, I try to connect the wire from the battery to the fuse and it sparks. This time it left a tiny black mark on the gold connection that the wire from the battery touched, however I looked at the fuse and it did not look broken. Now I am very confused on what could be wrong. My setup worked fine before, the only difference is that now instead of having my capacitor before the distribution block, it is after the distribution block so it only helps the subwoofer amp out. My amps (unless I am mistaken) should not be drawing any current because the car is not on and the remote turn on wire isnt telling them to turn on.



Edit:

I tested it out and found that it was my capacitor that was bad. My ground was the right ground to begin with, I just can't understand why or how the capacitor shorted out. It was touching the right power/ground, it must have somehow shorted out while it was out of my car. No clue how this happened, I just see that there is no resistance when I put the multimeter on it. Just making sure, this means the cap is useless and as good as 5 pound weight now, nothing to do to save it?

I put in a new capacitor that doesn't have a voltage readout, but that seemed to do the trick. Does anyone know if there should be an "on" light that turns on when a capacitor turns on in all cases? My old cap did because it needed a remote turn on wire for the voltage level indicator, but since this one does not have an indicator, it doesnt have a remote turn on and the one spot that possibly looks like it could light up, doesn't. It is a lightning audio strike capacitor without voltage display, just regular one.

[ta2dSi]

capacitors don't turn on.. they impede the change in voltage.... that is why they charge up and discharge.

By saying that there is no resistance, are you saying it is open? which would be infinite, or no resistance as in 0 ohms?

If you are reading 0 ohms, then yes the cap is shorted out... If you are reading infinite ohms, then it is open, and it is shot. (BTW make sure you are on the correct scale when doing this.)

Either of the 2 it is now a nice paperweight.

The only way that a light could turn on, on the cap is when it is charging or discharging since that is the only time there is a difference in potenial on the 2 cap terminals. Once it is charged, and electricity is running through it, it is almost like it isn't there. Where the Cap does it's work it on the discharge when the power is gone, and slowly discharges.

I hope this helps ya out

[napapacoda]

Originally posted by ta2dSi
capacitors don't turn on.. they impede the change in voltage.... that is why they charge up and discharge.

By saying that there is no resistance, are you saying it is open? which would be infinite, or no resistance as in 0 ohms?

If you are reading 0 ohms, then yes the cap is shorted out... If you are reading infinite ohms, then it is open, and it is shot. (BTW make sure you are on the correct scale when doing this.)

Either of the 2 it is now a nice paperweight.

The only way that a light could turn on, on the cap is when it is charging or discharging since that is the only time there is a difference in potenial on the 2 cap terminals. Once it is charged, and electricity is running through it, it is almost like it isn't there. Where the Cap does it's work it on the discharge when the power is gone, and slowly discharges.

I hope this helps ya out


Thanks for letting me know. Yes, it is reading 0 ohms. Nothing like a nice $100 paperweight. I'm now questioning if the bodyshop did this as I remember that I left the capacitor in when I gave my car to them and I saw they moved around some of my other car audio stuff when they worked on my rear end damage. I can't see how I shorted it out. Either way, I can't prove they did it so im fucked.

When I charged my (new one I just installed) cap, I measured it out and it showed 7v, but then once I connected the power source (battery) it went up to 12, so I'm guessing the new cap working fine right now.

I guess its not so bad to keep spare parts lying around in case shit like this happens.