Can I Get A Little Help???

[EngineGarageGuy]

Hi everyone.
I need a little help with a car that my mom owns. I know a lot about cars, until it comes to wiring. This problem that I am having is to do with the radio of a 91 Geo Metro 4Dr Hatchback.
Ok, a little over a year ago the radio stopped working. Until now we didn't try to really mess with it because this car is only used when painting houses and stuff. Now it is bugging me though. When I took the cover off, the red light was flashing on the deck. I checked all the fuses earlier, and they were all good (I figured they would be). Anyway, I took the deck out as far as I could and found that the biggest cable was disconnected, so I reconnected it. Nothing happened. So I thought that it was the ground wire. I began tracing it down and there was a black box with a fuse inside. I popped it out to check it and got a spark fly up at my face. I disconnected the battery so that I could safely put it back in. Then, I reconnected the battery and the red light stopped flashing completely. So now I need to know why the red light stopped flashing and what it's purpose is for in the first place? I know it has to do with the reset button, because when I pushed that in it stopped flashing completely when it still worked. Also, I still need to fix the radio!
Thanks for any help that you can provide.

[PaulD]

the flashing red light is typically for the anti-theft feature.

[EngineGarageGuy]

That's what I thought, but this car has no type of alarm system. I looked on the bottom of the deck though, and it said that it was manufactured in 2000. It must be aftermarket.
The red light also stopped flashing when I pressed in the small reset button.
Any ideas anyone?

[PaulD]

if it's aftermarket, pull it out and give us a manufacturer and model number. that might make it a lot easier.

[EngineGarageGuy]

The Manufacturer is Koss and the model number is MS510.
It is a crappy radio, but I just want to fix it.
Any more help would be appreciated. I think that it is the ground wire, but I need more help determining where the problem is and what happened with that fuse and red light for "reset" and all that.
Thanks

[PaulD]

I didn't even know Koss made CD players. Some units use to have a small box on the power wire about 1/2 - 3/4" ... sometimes the black and red wire went into the box. It's really just a power line filter, you must have shorted something out ot make it spark.

[EngineGarageGuy]

There was a little box for the red wire too. That wasn't where the problem was though.
You have been lost buddy Koss has been making cd players for a long time. No offense though.
The black and yellow (ground and memory) ran through a big black box with one fuse. They both ran through the same fuse by the looks of it.
That is what gave me the spark, but I don't know how.
Thanks and keep em coming if you can.

[PaulD]

does this unit have a sub-box ?

[EngineGarageGuy]

If you mean sub-box as in what I know of (sub-woofer) then no. If you are referring to anything else that I don't know of, then I am not sure.
So what should I start with? Should I take out that fuse or just go straight to the ground wire and see if it is grounded? Where should I ground it? To the frame where it should be and if so what part of the frame?
I am in no rush to do anything, I just want to know where to start.
Thanks to all

[PaulD]

no, I meant a companion box that goes with the headunit that typically has the power supply and maybe the radi circuits in it.

[EngineGarageGuy]

Ohh...I am sorry, I know very little about this radio stuff.
Yes, if you are referring to the round and about 1 1/2 inch long box with the power supply running through it (sounds exactly like what you are referring to) then I have that. I have not looked inside though.
Sorry about that. So what now ?
Thanks all

[PaulD]

actually, I was referring to a much larger box some of the old headunits use to have.

I guess you need to start from the beginning ..... there should be a wire that is ground (black), a wire that has 12 volts when the key is on (typically red), and a wire that has 12 volts all the time - memory - (typically yellow). You need to check EVERY fuse box to see if there is a blown fuse. There is usually a fuse block under the hood, check it too.