'86 911: How to get this blue wire re attached?

[Michael_1975]

Hi fellow Porsche enthusiasts,

My name is Mike, i've owned a (ROW) '86 Porsche 911 3.2 for 5 years now and have learned a lot from reading on this great forum. For now i was hoping anyone could help me with the following, so here goes:

I was putting back my big, heavy and recharged battery and while doing so, i accidentally disconnected this blue wire coming from the right front area in the trunk (see attached images). It seemingly was going to the fuse box (also attached).

I have looked everywhere but can't seem to find where to connect it. I'm afraid i'll have to unscrew the fusebox, which i'm not looking forward to... Do any of you have any tip or tricks? Would anyone know what purpose this blue wire serves?

Thank you in advance,
Mike

[Dpmulvan]

Doesnt appear to be a stock wire, do you have a cooling fan on your oil cooler?

[Drisump]

It appears to be an eyelet connector no? Looks like it goes to the positive terminal of your battery and not to the fuse box. If that is the case, there should be a line fuse somewhere. What does it power? Not sure, but you can start it up and check all systems for function without connecting the wire and that should tell you....unless it is something working in the background like an auxillary cooling fan as Dmul says. Cheers

[Drisump]

Does your meter show an active 5.5 volts on the disconnected wire....that would be a strange case?! If it is already powered, it should display 13 volts or so when a fully charged battery is installed.

[DRACO A5OG]

I would check each fuse terminal to see which one is has the loose bunch or single wire. Obviously it was not in too tight.

+1 not stock wiring.

BTW, Welcome Aboard , What is that a Venetian Blue Carrera?

[rwest]

Do you have an aftermarket stereo or power antenna? Blue wires are often used as the remote turn on lead.

[SpyderMike]

On my 1985 I show blue being high beam power for the left headlight and should be attached to the bottom side of the eighth fuse from the front of the car. A similar yellow wire would go from fuse five from the front to the opposite headlight. If someone rewired the headlights, then they may have switched them. Other than that, there are bundles for horns, turn signals and fog lights going through those penetrations. Any chance of some accessory in that fender area?

It looks to me that he is measuring battery voltage in the picture...maybe the reason for replacement.

[Michael_1975]

Thanks guys for all your feedback! The first pic indeed shows the battery’s voltage. Unexpectedly i was able to charge it back to 12.7 volts, not sure how long it will last though.

Anyways, the blue wire…The headlights (high beam included), turn signals, fog lights and horn are all working properly. There is no auxiliary cooling fan or other accessory i would know of. There is an after market radio (Becker Indianapolis), however the stock antenna is being used (in the windshield).

The picture below shows where the blue wire went into. The connector seems to be too big to connect to any fuse, as far as i can see.

Any more thoughts?

PS Draco, it's a midnight blue carrera

[SpyderMike]

yikes...the wire on top of the next fuse right (red) looks dangerous, like it was shorted and melted the insulation. You might want to check/fix that. That comes from the light switch and is for a side marker light most likely and should be grey/black.

Power comes in from the top and out the bottom of the fuse panel. A solid blue feed wire to the headlight would be on the bottom, one fuse to the left of where you are currently holding the wire.

That blue wire you are holding is on top of a connection that normally would be tied to the one next to it left (yellow wire) so that it has power when the headlights are switched on. That yellow wire on top, one left of where you have the blue, is the power feed from the light switch.

That blue wire you hold may have been installed to solve the melted wire issue to the side marker somehow??

Oh, and that red fuse 16amp should be a yellow one 5amp. That may be why that wire ended up melted instead of being protected by the fuse.

[zippy_gg]

Michael, do you happen to have an aftermarket horn (replacement or add-on to stock)?
You should check under the car and forward of the external oil cooler...

[Michael_1975]

Guys, thanks again for your feedback. I'm not aware of any aftermarket horn. I'm gonna try to look into things this weekend.

Cheers.

[Michael_1975]

Today i already managed to unscrew the fusebox to take a look at the "back". I found a red wire which had the same type of connector.



However this one couldn't have been connected to the blue wire; i did not find anything else where it could have been connected to.

Looking at the point where the blue wire emerges, i also noticed this brown wire which isn't connected to anything.



I guess the blue wire wasn't connected to anything anymore either. What do you guys think?

[CCM911]

Unfortunately, you are going to have to trace the blue wire back in order to determine where it terminates.

[SpyderMike]

Looking at the extra fuses behind your fuse panel says that someone has wired some modification in (blue circle). Red/White (green circle) could be one of a couple of things.


If everything on the car works to your satisfaction, then I would just cap and stow any wire like this.

Brown is typically ground, and that wire would be going through the foglight penetration. Have you looked under your bumper to see if the other end of the wire is there?

[Michael_1975]

I looked under the bumper but couldn't see the other end of the cable. I've just isolated both the brown and blue wire. Everythings seems to work fine, so i guess i'll just assume the blue wire went nowhere.

Thanks again for all the feedback!

[rattlsnak]

The only way to solve this, is to trace the blue wire back and see what/where it connects to. Some things on the right side under fender could be horns or oil cooler fan or who knows what else but the blue wire is definitely not stock.