Frayed Alternator Harness (?) & Burnt out Starter Motor Questions (2007 VW GTI)

I have an '07 VW GTI, manual, stock, with 88,000 miles. VW replaced the engine at the tail end of the powertrain warranty due to engine oil loss problems, but I don’t think this is related to my current problem as it was so long ago. I should also state that I bought and installed a new battery approx. 3-4 months ago.

My current problem is that my car won’t start. Drove it to a friends, hung out, got in it to leave, the engine turned once and then nothing. Tried to crank it a couple more times, but nothing. Electricity was good - headlights worked, all power systems worked in the car, but nothing cranked. No sounds afterwards, either, other than a very high-pitched wheeeee sound (electrical system turning on?).

Opened it up and saw that the alternator harness was nearly frayed in two just below the fuse box it comes out of next to the battery, with hints of battery acid exposure at the fray. So I got it towed to a mechanic and they said that although there was electricity at the starter, the starter was burnt-out (they think it caught fire or melted internally).

Here are some semi-blurry pics I snapped with my phone camera of the general area of the engine compartment and close-ups of the starter motor and what I’m calling the alternator harness (frayed part).

I have some theories, but I thought I’d open it up to the community here. I have three basic questions:
(1) Has anyone else had this problem or a similar one on a Mk5 VW? Any suggestions?

(2) How could battery acid get past the fuse-box and into that harness? Is this what caused it to fray, or did it come loose and rub against that bracket? Has this happened to anyone else?
(FYI I saw NO indication of battery acid dripping from the battery itself, just what looked like acid remnants where the wire was frayed.)

(3) What should I expect in terms of cost for a new starter and new alternator harness? Is it difficult to change out either of these parts?
(The mechanic it’s at now tentatively quoted me just north of $1000 ($230 starter, $150 harness + labor) bc they weren’t sure how much work was involved in installing the harness.)

Thanks for any help you can provide!

YA…what happens is that the batteries actually seep out Acid around the posts of the batt. I dont know why but they do. A dry Cell batt solves these issues but of course they cost more so forget getting one as OEM equipment.

You should be able to swap out a starter and alternator harness no prob with fairly basic hand tools.

Go to a U-Pull-It Salvage yard and grab some parts on the cheap…Even the Alt harness. ALSO grab a new Batt cable…is that your neg cable? If so those are easy to remove in the yard…looks like yours is on the way out. You should get out of the Yard with spending about 80 Bucks or less… Then its up to you to do the repairs. Also clean off the battery and surrounding areas…remove the batt…the batt tray and hose it all off… YOu can also neutralize the spilled acid with Baking Soda…or other chemicals. Then buy some of those chemical treated donuts for the battery posts to prevent further acid issues.

Hi Honda Blackbird, Thanks for the reply and the good ideas!

The frayed cable is the harness that comes out of the fuse box next to the battery and snakes down and the across the front of the engine to the alternator.

Re: battery acid seeping out of the posts, I didn’t see any evidence of this, or of battery acid running down the harness. Just what looked like acid remnants at the point where the harness was frayed.