Important electrical issue for all VWs

[Multi69s]

Moderators - I know this is a double post, but it is also important

Well I just lost (melted) the entire electrical loom starting from under the back seat to the rear of the car on my 69 Baja (converted to alternator). This is bad enough on a stock bug, but I have a lot of extra wiring as well. I have all the additional wiring for my gauges, plus since I tow a small dirt bike trailer, I have a turn signal converter, and also trailer brakes. Now all of these wires are fused into a solid mass. So what happened?

I started it up to leave for work, gave the throttle a couple of blips to clear it, and then the engine died. What the ? I went to start it again, and I saw smoke in the rear view mirror, so I jumped out and ran to the back. There was a massive short between the alternator output wire and the fan shroud. Time being critical, I grabbed my tool box from under the hood, dug out some wire cutters and cut the alternator wire in two (burnt fingers). Once the smoke cleared, from outside and inside the car, I looked for damage.

On an internally regulated alternator, the alternator output wire is connected straight to the battery, so it always has 12V. Part of the insulation of this wire, must have worn through, then grounded out to the fan shroud. The result was that ALL of the insulation was burned off of this wire from the point of short, all the way to the battery. Since this wire is ran through the main loom, the temperature was hot enough to melt all of the wires together in the loom at the death foam area of the car. As I rewire the car, I will be moving the route of the charging wire away from the main loom.

I am usually pretty good about maintenance on my VWs, but I just plain missed this. Since it was a Baja, it must have been on the backside of the wire. Some of you may flame me, I can take it. I can also fix it, but others may not be able to. That's why I'm posting this. If I can help prevent someone else from facing this dilemma, I'll gladly walk the walk of shame.

So the moral of this story is to keep an eye on your generator / alternator charging wire, if at all questionable, replace it or put an insulating sleeve on it.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[ach60]

How big of a fuse, or a fusible link would I need to protect this circuit?
_________________
Good Luck
Al

[Multi69s]

[67rustavenger]

Multi69s, I really don't think anyone is going to flame you for an honest post about a situation that happened to your car. Thankfully you were quick thinking enough to cut the positive lead to the battery before there was a complete melt down to the front of the car.
I have posted all of the dumb stuff that I have done to my car over the last couple of years and the response has been on the positive side of things.
We all want the best of our friends and corespondents here on the samba.
I hope you get it back on the road soon.

Good Luck.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[Bama Dave]

Thanks for the post. I am just a few days away from hooking up all the wiring in my Baja, including the new alternator. I will be sure to protect that wire a bit better than I may have.
_________________
David Richerson

1970 Beetle
1971 Super
1972 Baja

[vwkirb]

That wire should probably be in a loom for just that reason
_________________
Andrew Kirby

[vamram]

Man, that sucks but glad you caught it "in time" and thanks for sharing your findings. I'm about to drop the engine on my '72 Super for other maintenance work and will add this to the list of items to possibly re-engineer.

Just to be sure, this would be one of the wires that runs to the 4-wire junction under the driver-side rear, correct?
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[Multi69s]

That would be correct. I stole this picture from the gallery, and they wired it a little different.

The wire is the red one coming out of the chassis labeled "to alternator". All of the insulation was melted off of it, plus it passed through the junction, and burned off the insulation on the black wired labeled "to battery". So all of the wires that are going through the black grommet into the chassis were melted together. I am rewiring it right now, and instead of running the alternator wire through this loom, I will use a grommet and run it down the passenger side straight to the battery.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Joel]

Even my 74 Celica had a fusible link on the main battery wire, never got why vw didn't.

I Run a circuit breaker on mine at the battery, saved my bacon already when the main wire pulled out of the connector block at the regulator and hit the heater Y pipe.
_________________
Quick little bug, you got a Porsche motor in that?
1974 Germanlook 1303 2.5 Suba-Beetle

[Multi69s]

I plan on running the alternator wire straight to the starter #30 I believe. Then pull power for the car off of the battery, and fuse it.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[richardc]

Got to love Scotch locks!
_________________
1970 Ghia vert
1970 Beetle sedan

[EVfun]

[ashman40]

[Multi69s]

Got the Baja wired and ready to go. It was hell of a lot of work. If I had the time, I would have ordered a harness and started fresh from front to back. However, I was on a time constraint since we are going to Pismo in a couple of days. Luckily I had some partial looms in my stash, so I had just enough wire (correct colors) to go from under the rear seat to the engine compartment, that meant one hell of a lot of wire striping, soldering, and heat shrinking (not a crimp connector in sight). Also when I ran the loom through the pillar, I used a heavy duty solid loom protector, not the split crap you get from a FLAPS. I also made my own charging wire, but it doesn't go through the loom, but now it goes to the starter, and is supported by a clamping system that is attached to the firewall.

I have wired and rewired many different VWS, from rails to sedans. For me this was a HUGH pain in the neck, and I was very lucky that the car did not catch on fire. For the average VWer this would have been a total nightmare.

So please take it from me, it doesn't matter if you have a generator or alternator, but inspection of the charging wire should be on everyone's maintenance list. Especially where it runs behind the carburetor. At that area, you cant see if and where it has been rubbing for the last 40 years, and all it takes is on small nick in the insulation to have disastrous results.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Cusser]

[garyt]

Similar happened to me when I (stupidly) jacked the car up by the engine once, it's an FI and the post on the alternator hit the underneath of the air flow meter and shorted, luckily I smelled the heat and unjacked the car pretty sharpish but some wres had melted a bit. The rubber boot on the little hood on the post had split. I should have disconnected the battery of course.

I cut down the alternator post and put on a new VW boot which fits better, plus a new wire.

[goober]

".....but inspection of the charging wire should be on everyone's maintenance list."

Sorry about your loss but thanks for the heads-up. I'll check over my cars today.

[Multi69s]