ign. wiring harness help

[OneEyedWilly36]

Hey out there im new to vortex but ive had a lotta help from the forums. so i just bought a 97 jetta vr6 and ive been havin some wiring trouble. im alright w wiring but not the best , when i bought the car the black wire in the harness from the ign. cylinder down to the fuse block, the insulation was melted. i replaced the harness... same thing. so i replaced the harness and the fuse block since there are no other wire(that i could find) melted or shorted.. started and ran for a few min.. then i started it about 6 more times... no problems... then i drove it around a little shut off ign. and when i went to start it back up it would only crank , no start and the same wire melted again.. im kinda stuck on what to check/replace, im waitin on my bently manual to come in the mail, but im just stumped on what the source of the problem is.. and guidance as to what i should check for next would be greatly appreciated, i really wanna drive this car but its drivin me crazy. any insight would help.... thanks, aaron

[Uncle_Jesse]

Change you're ignition switch

[OneEyedWilly36]

ok.. i was thinkin that.. it just seemed wierd that it would do that but ill let ya know if it works.. thanks for the help

[OneEyedWilly36]

ok so i replaced the ignition switch and put another harness on... started up a couple times and let it run a couple min, then shut down and restarted.. and it would only crank but this time the ground wire on the harness is ok but a ground in a white plug(connects to the fuse block ) in G1 was melted not the whole wire but just the connection part in the plug. so im back to where i started..

[Uncle_Jesse]

Have you ever replaced you're alternator ?

[bonesaw]

what wire on G harness? Id check and clean all your grounds.

[OneEyedWilly36]

The alternator looks newer but i just bought the car about a week ago. and its the black power wire on the g harness.. the first time it happened the black wire was burnt. replace that section and now it melted just a little (same wire) but only in the connector.

[bonesaw]

Black is not ground. It is switched ignition. Power to your coil and vss

[OneEyedWilly36]

oh ... well i checked w my test light w the plug unplugged (black wire) at the end that plugs into the fuse block and there is ground to it, and it had ground w KOEOff and while cranking.. would it be possible and fairly painless to just run new wires to coil and vss

[Mr Tomski]

i'm having this exact same issue on my 99 glx..
when i checked in with a seasoned local vw mechanic, the first thing he asked me is if my radio shut off and if my abs lights turned on - which they did.

upon testing my battery, off a cold start it took a minute or two to get up to optimal voltage
and i also noticed after about an hour of highway driving the car falls partially under load when i hit a red light after getting back in to the city - and the abs light triggered again and the rpms dropped slightly for a moment.

i have a feeling that my alternator is on its way out, probably all original from date of vehicle purchase.
i should be getting it rebuilt next week, if your issue persists, i will let you what's going on with my situation.

[VDub2625]

First off, sorry about the bad advice above, the ignition switch is obviously not the problem. The black wire is the ign/start power, it's the wire that powers the ECU, etc, anything that isn't cut out by the starter. So something there is shorting out.

What fusible link? There are none. And what wire on which G harness?
This might help with identifying what wire, see the graphic at the top and the chart:
http://www.a2resource.com/electrical/CE2.html

Before you start running new wires, it's more likely a component problem.

[OneEyedWilly36]

.....Its wire 4 on G1 harness. and thanks for the help.. greatly appreciated ....cant get back up to work on it till tomorrow but hopefullyill have a little more info on it.

[OneEyedWilly36]

ok... i got my bentley for myjetta and did the ign coil test that is described in the book found term 1 on the harness(not plugged in) to have about 4V and is supposed to be 12v and that wire(the shorted wire) is my problem wire on the fuse block under dash. so for ****s a giggles i ran my own 12v ref to the coil, the VSS, and cam sens. that is all that it looks like the 12v wire feeds. and still nothing. so i continued the coil harness test and connected test light between term, 2 and 5, 3 and 5, and 4 and 5. and cranked car... the test light was supposed flash but didnt... so that leads me towards ecu but i had the car starting up for a few minutes a couple weeks ago so i would think the ecu wouldnt be the issue...but ya never know... and also i noticed that my dash lights do not light anymore but clock and milage work. all fuses ok......and yet again.... stuck ,any help will help

[VDub2625]

Just throwing it out there for a test, but the ECU won't send a signal to the coil if it doesn't see a cam sensor (and maybe crank sensor) signal. It doesn't know the engine is turning in that case. Likely not the problem, but something to rule out.