No power, no start, no lights. Replaced battery and same problem

I recently posted a thread asking for help with the battery fuse box melting, lots of good feedback thank to all who replied. Now I'm having another issue, possibly related. Car won't start, no crank, no noise, no lights, no clock just nothing. Jumped it and nothing. Replaced battery and nothing. Checked fuses inside and on fuse box on battery all look good. Cleaned battery wires too. The only light that works is light on my car charger when plugged into cigarette lighter. Anybody out there have similar issues with their Jetta?

It certainly is related.
When you turn the key to on, nothing lights up on the dash?
My fuse box melted a bit years ago, but it was coolant fans stuck on and running. You have a different issue, but something caused excess current flow, likely stuff is up front, but you might also check the wires up near the fuse box and relays inside the car. Remove the lower dash trim panel (and?) so you can see better. Maybe find the grounds up there as well.

Nothing happens when I turn key. Dome light won't turn on when I open doors. No horn. No dash lights. Usually the clock on dash is always lit but now nothing.

Hmm, might be a long shot but there is a fuse (end of dash) that causes a lot of those issues if it popped. Little 7.5A fuse I believe.

Other wise get a volt meter out and start checking for where the power stops.

Jason

Grounds located under the battery box, perhaps?

Thanks everyone for your comments. I found the issue - so far at least. Turns out the battery is shot but like I said even the new battery didn't do anything. The black wire coming from alternator which I had replaced less than a year ago was corroded "green stuff" I cut the insulation back about an inch and it was covered with corrosion so I cleaned it as best I could and put it all together and sure enough dash lights, clock, horn all came back. Car wouldn't start until I jumped it, let it run for 5-10 minutes then wouldn't start back up. Bad battery but at least I found the issue

The question now is why is this cable corroding so much and so fast? This is the same cable that melts the fuse box (one on far left) I replaced the original cable with this ticket gauge cable but that didn't help. Still gets crazy hot and corrodes easily. Anyone know why? No other car over ever owned has had this issue. Is this just one of those things with VW Jetta? I've seen tons of stuff on the internet about this. They all show how to fix aka clean cable but haven't found why it happens in the first place. Just how to fix once it happens which seems to be very often.

Have you checked your alternator output with a volt meter?

There is either a large current draw, or substantial resistance in that circuit somewhere. I've had two MkIVs and with over 12 years and 170k miles between them, no melted fuse box. But I'm also OCD about keeping the battery and fuse panel clean, because I work on them every day.

Corroding could be venting from the battery, compounded by the charging issues.

Start with volt meter on the alternator and check its charging output. 14.1V is great, but may vary between 13.8V to 14.4V. It's possible that you may have a over charging issue causing the battery to out gas excessively. Next check voltage at battery - should be close to reading at alternator when there is little load turn on.

We'll start there and see what you find.

Jason

So I replaced the battery and car turned on. I changed oil then was going to check volts with multimeter as you all recommend but read 0 volts I went to start car and nothing. Same issue no lights, no clock no power. I took off the wires to clean them again and nothing. Must be a loose wires somewhere or the wire that comes from alternator (the one I cleaned yesterday) is corroded even further down. It's new not even 8 months.

Seems like I read on here somewhere that wire is #4 gauge, or should be. If it's green and corroded regardless of age you will need to replace it.

If you have a multimeter check your battery on the posts with the car off. (Not running) The reading should be around 12.6-7 on a healthy battery. Now check the voltage on the cables themselves right on top of the battery where they connect to the posts but don't touch the posts themselves. The reading should be the same. Now check the other end of the battery cable at the starter, the reading should be the same as you get on the posts of the battery. If not replace the cable.

Get a new one from the dealer, or a good used one from the junkyard, where the fuse box shows no sign of melting. You may want to grab a fuse box like that in addition to the cable. If you go new don't buy cheap Chinese junk.

Now start the car if it will start. What reading do you get at the battery? You should get in the 14.3-7 range, significantly more and you're overcharging, less and it's not enough to keep your battery charged and run all your accessories. Walmart has digital multimeters for around $25. Set it to 12v and start checking.

Those treated felt battery washers help keep corrosion at bay, along with a good spray for the terminals. The battery "diapers" are nice too if you can find them.

It might be just as easy to pull the starter and alternator and take them to get tested.

Here's the latest. I replaced the wire coming from alternator and its running good now. I went ahead and ordered a new fuse box and just installed it. I used some battery terminal grease and it seems to running good. I drove it for 5-10 minutes and checked the temperature of the black wire coming from alternator with hand touch and it isn't any hotter than the cables next to it. Warm not blistering hot like before. It seems like it was a combination of bad battery, bad corroded cable and melted fuse box that caused the no lights, no clock no nothing issue. Thanks everyone for your help

Maybe take the car to Advance Auto and have them do a check on the charging system-say you were having electrical problems and just wanted to see if the alternator/battery are ok.....