What is this black box in rear trunk near ECU?
 

http://986forum.com/forums/uploads02...1514684535.jpg

What is the black box to the right of ECU on this 1999 986 manual? This is the kind of wiring you do NOT want to find when troubleshooting a no-start situation. The mystery box has 2 wires coming out of it: red and black and they connect to a yellow and black wire from the harness.

It looks maybe like a remote starter as I "think" the yellow and black are ignition and starter.

Any guesses and any idea where the yellow and black wire should go instead of this box ? Thanks in advance.

GPS vehicle locator, i.e. Lo-Jack type device?

Wow, what in the heck are all those solderless connectors going to? That’s a lot of hacked in wiring!

I believe that's the "flux capacitor". Be careful around 88 MPH.

Just sayin'............

TO

:D:D:D

The black box would not concern me as much as the other wires in the picture. I'd just rip it out along with the rest of the hacked up engine harness. Unless you know details of what that mess is meant to do, it will probably solve a lot of problems to replace it all. You have me curious if there is anything strange on the other side of the firewall... Stock 2.5L?
Is it your car? ...more pics plz.

...and it may take me a couple days to get around to it, but I have full schematics available if you need them.

You posted much better pictures on the “R-list” site. And based on those, you need to loose all that junk, whatever the heck it is.

Yes, the other post is better. I'm still curious about the engine - and the rest of the car. The other connector in question in the R-list post is for the trunk light. Here's a pic of it on a harness:
http://986forum.com/forums/uploads02...1515006366.jpg

Curious as well. No idea why there would need to be all of those fuses inline in that section. Very odd.

Wow, what the heck is going on in your trunk?

You might want to ask Homeland Security to take a quick look ... :D Just be careful and don't cut the green wire..... Or was it the red?

http://986forum.com/forums/uploads02...1515044025.jpg

Many thanks for all the replies. Black box was a 6v battery that is now out of the car. I'm guessing part of an old alarm system or IED. Didn't blow up yet anyways. ;) It had a yellow and black wire that run towards the front of the car and looks a lot like the cruise control clutch switch wires which is just bizarre. I'll get some more work done on it this weekend and let you know what I find. As for the engine (swap, etc) that's a good point and I haven't checked to be honest! I'm going to do the 1 and 7 relay bypasses to see if cranks. Also bypassing the clutch switch.

Thanks for the post about the trunk light, I'll double check that!

I also have the service manual so I'll eventually figure it out and then do a data dump of all I've leaned about whole ignition system (DME, immobilizer, clutch switch, rfid pill, programming, etc.).

Be careful of the flux capacitor. :D

http://986forum.com/forums/uploads02...1515131912.jpg
http://986forum.com/forums/uploads02...1515132029.jpg

Couple photos of the project with and w/o hardtop. Everything works except remote buttons and it won't crank. Smells like rfid pill or previously wet immobilizer but only more diagnosis will tell. Going to get a durametric or top of the line obd reader. Thanks for the help.

Oh man, you could have a genuine Porsche electronics nightmare on your hand. Is it possible someone tried to bypass the onboard security? Which is almost impossible. If the remotes don’t work it’s possible you have a fried immobilizer. I remember reading somewhere that the car will can go into a sleep mode, if you will, after a time. I believe it’s covered in the manual. I don’t recall the specifics. Do your keys lock and unlock the door manually? Check to see if the “little green pill” is inside the fob, or if it’s broken. The key won’t work unless the whole system can talk to each other, and the little pill in the key is the keymaster...

I have one possible theory. Mice/rats love to chew on wires in the trunk. It's their second favorite spot. On top of the engine is their favorite nesting spot. Maybe a mouse/rat got up in there and chewed those wires. The owner replaced the chewed wires with that.

Quick update, car is starting and running like a champ now. I ended up buying a used set of ecu, immobilizer and key fob off eBay for $500. It was easy to swap the parts and transfer the key blade to the new fob. It is worthwhile to note the 986 and 996 share the same parts here. I'll post more later as I have lots of tips, with photos and write ups on how it to get around various starting problems. Thanks for the replies, especially the trunk light wiring one as that helped a lot.

Glad you got it sorted! But, you haven’t answered the burning question... what the heck were all of those wires, and what were they doing, bypassing or whatever? Curious minds want to know!

I think Woody nailed it. The PO probably bought an inline fuse bundle to repair the harness.
http://986forum.com/forums/uploads02...1515417734.jpg

Good for now, but for long term, a replacement engine harness would be best. You may be able to scrape your knuckles and install a harness with the engine in, but Probably best to wait until you are doing some more major maintenance and drop the engine. Especially if the car runs & drives well for now.

I actually don't know. Woody could be right or maybe the previous owner didn't know you need a good RFID to start and was trying to bypass something. But, it's working now and the one thing I've learned over 20 years of DIYer fixes on my cars is: if it ain't currently broken don't fix it; if you do, it will likely be broken soon ;)

Now, as for bypassing the rfid pill I do have a good working theory on how to do it. Nothing I'm worried about a thief doing in 60 seconds as it would take more than an hour to get at all the parts. I think I'll write up a formal post and ask for feedback so this thread doesn't get hijacked.

Best.

wonder if PO was tracing a batter drain or an intermittent short circuit seeing its the red/blue cables mainly arent they power feeds?