Starter wiring

FieroGT42

Member
Joined
Apr 25, 2006
2005 Passat TDI auto.
Girlfriend's prior 2 mechanics were s***. Last one did an engine swap and screwed up all kinds of small things. Car now no longer starts. It started 1 out of 100 times and ran perfectly. The other 99, it gets to the point where the solenoid should engage, but it doesn't.

I get about 0v key off and ruin position, maybe 1 to 1.5v on the solenoid trigger wire in the start position.

The load reduction relay clicks every time I turn the key, so I think the ignition switch itself is good unless it runs off a different signal wire on the same switch.

I don't know where to trace wires now. Where exactly are all of these wires run? Is there a diagram? I haven't seen one in the Bentley manual that shows the in-car routing.
 

afarfalla

Veteran Member
Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
he forgot a ground wire, The one I missed on my swap was under the break reservoir on the fire wall
 

FieroGT42

Member
Joined
Apr 25, 2006
I tested the voltage from the starter trigger wire and the constant 12v to various grounds. How would it be a ground if it reads 12v to the battery but not on the trigger wire through the same ground path?
 

FieroGT42

Member
Joined
Apr 25, 2006
Ground is fine. Solenoid wiring tests okay. It seems the (lying ***hole) idiots at Bass Automotive in Belleville, IL managed to install the engine in such a way that not only is the main wiring harness pulling its full weight on a few sensor wires around the coolant bottle area, and the main grounds and starter power cables are hanging loose with their brackets rattling around... but the transmission cooler lines are somehow electrified with full battery current (~900 amperes?) upon engaging the solenoid, which shorts to the engine mount with enough power to not just vaporize the rubber instantly but create a puff of air.

I've never seen a wire this completely buggered. It boggles the mind.

Now I get to trace that on a car which is really hard to trace wires and hoses on because of the cramped engine bay. On the upside, there are only so many places for that amount of current to pass through.

https://youtu.be/S5Z2LTohHf4

 

FieroGT42

Member
Joined
Apr 25, 2006
There is a heavy ground cable running from the chassis to the engine on the right hand side engine mount bracket. It is usually positioned to rub a hole in the turbo to crossover pipe hose. That's likely where your problem is.
What are you talking about?

The heavy cable contacting the turbo-to-crossover hose is the positive 12v to the starter directly from the battery. The starter is then grounded by a cable from its frame to the cast engine mounting bracket. The case should also ground through its mounting directly.
http://www.myturbodiesel.com/wiki/starter-testing-and-removal-b5-passat-tdi/

Without a short from a HOT wire to something that should be grounded, there wouldn't be current arcing anywhere. It isn't just a bad or missing ground. Electricity doesn't work like that.
 
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vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Kudos QTD for handling that well. Merry Christmas :D
 

owr084

Top Post Dawg
Joined
Oct 20, 2004
Location
Northern Virginia (NoVA)
TDI
Passat GLS, 2005, Stonehenge Gray
If you are in Belleville, you are right across the river from oilhammer, the best B5.5 TDI mechanic in the country. Take it to him!
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Oh don't drag me into this mess, LOL.

Although it would be both humorous (and heart wrenching) to see this poor car.

It does sound like a missing ground wire to me too.... but maybe I also don't know electricity works. :p
 
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