show me your diy GP harness

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
I like this. It seems like your wire size might be overkill when you compare it against the stock wiring but that's not a bad thing.
No doubt.

My view was : each plug draws upwards of 15A inrush when cold, so non-trivial currents are involved and I always thought the factory wiring seemed on-the-edge.

Also, every milliohm of extra resistance is that much less voltage delivered to the business end of the glow plug... at the airport after the car's been sitting for a week... in -30C weather.

So, cheap insurance against problems caused specifically by my wiring. :)
 

blackty

Veteran Member
Joined
Jan 29, 2012
Location
Bangor, Pa
TDI
2000 Jetta tdi (sold)--2005 Jetta 2.5 Tiptronic---1993 GMC Typhoon---2003 2500HD Silverado---2012 WRX Wagon
Right click-add to favorites...Jim
 

tditom

Top Post Dawg
Joined
Sep 5, 2001
Location
Jackson, MI
TDI
formerly: 2001 Golf GL, '97 Passat (RIP) '98 NB, '05 B5 sedan
Vince, will a second nut fit on the threads? You could create a ring terminal sandwich with two nuts and clamp down very snugly. There doesn't appear to be much of a shoulder for the ring terminal to engage on the gp.
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Sure, there's probably enough threads for two nuts. Having said that, it's threaded for #8, so spade lugs with a #8 hole actually fit pretty tight and with a pretty good amount of lip on the other side against the top of the glow plug.

Either way would be fine IMHO. :). There might be some advantage to pinching the lug between two nuts.

Meanwhile a bunch of German engineers are shaking their heads at how over-engineered and over-analyzed their simple system has become. :):)
 

compu_85

Gadget Guy
Joined
Sep 29, 2003
Location
La Conner, WA
TDI
... None :S
I went to test my glow plugs yesterday (the check engine light has been on for a while). As I touched the harness it crumbled.... oops! As I looked at the date codes and the wiring I noticed it was still the original harness! 13 years isn't a bad run... but I need the car for Monday. I found I had the right size crimp connectors in my stash and made myself a harness.



They're the type with heatshrink and glue, so I feel this should last a good long time. All the plugs still tested good :cool:

-J
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Just replaced the harness on my wagon. It had the first one replaced under warranty at 48K, I suspect it didn't need it. This one lasted 235K. And it's been on and off many, many times as I do a lot of injector swaps. I can't see why anyone would complain about that kind of service life.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
I can't see why anyone would complain about that kind of service life.
Because we've heard of dealerships charging many hundreds of dollars to replace them - sometimes needlessly, as you suspected of your original encounter with this... (remember the $900+ glow plug and harness change that someone around here was charged?)

Yuri
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
Just replaced the harness on my wagon. It had the first one replaced under warranty at 48K, I suspect it didn't need it. This one lasted 235K. And it's been on and off many, many times as I do a lot of injector swaps. I can't see why anyone would complain about that kind of service life.
Why, because we are cheap, ;) and it shouldn't fail. My van's GP wiring is 30 years old and working just like it did when it was brand new.

Awesome thread, I didn't want to shell out $80 for some wiring so I'll be making my own very soon, tired of that damn light. :mad:
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Yes. Both sides get 12V, and the system monitors for a difference in current flow between the two sides.

If you're not getting 12V on both sides there's probably a upstream harness issue or a problem with the glow plug module.
 

nytoy

Veteran Member
Joined
Aug 14, 2008
Location
rochester, NY
TDI
1999.5 Jetta
Yes. Both sides get 12V, and the system monitors for a difference in current flow between the two sides.

If you're not getting 12V on both sides there's probably a upstream harness issue or a problem with the glow plug module.
Awesome thank you for the response, where is the glow plug module located? I found a box with two relay's but I unplugged them and it had no effect on the voltage at the glow plugs. Thanks!
 

nytoy

Veteran Member
Joined
Aug 14, 2008
Location
rochester, NY
TDI
1999.5 Jetta
yeah one wire is still dead, anyone know what the relay looks like or where the under dash wiring feeds those two wires?
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
What GP's did you use? I gotta do this soon, winter is coming.
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur

Dorkage

Veteran Member
Joined
Aug 27, 2010
Location
Thunder Bay, ON, Canada
TDI
2003 Wagon TDI, 2004 Golf R32
You get to add the threads yourself.
Cheers!
PH
How hard is the material on the end of the glow plug where you added the threads?

The Significant Others car has a constant glowplug code and takes forever to start with brand new glowplugs, so I'd like to make a completely new harness without paying VW Tax.
 

FastDiesel

New member
Joined
May 26, 2009
Location
Atoka, TN
TDI
01 Beetle, 98 Cummins 12 Valve, 94 Gulfstream 36' 5.9
Had 2 dead glow plugs (#2,4) on the daughters '01 Beetle. You've inspired me to build my own cheepo GP harness if I need one.

Now off to Autozone with a 2 year old battery, that won't spin the little TDI fast enough to start, when its below 30 deg F! With 2 more GPs pulling juice, it will really be slow! It's going down to 9 degF tomorrow night. Gotta get that little oil burner starting better!
 

DanEboy

Veteran Member
Joined
Mar 26, 2003
Location
Commack, NY (Long Island)
TDI
Jetta GLS 2000 Auto
I don't have a picture right now, but...

I had a issue with my GP harness once so I cleaned connectors with contact cleaner and very light use of a tiny round file.

Problem appeared again within a week.

I noticed that the connectors weren't that snug on the glow-plugs so I removed the harness and slid very small fuel line size hose clamps over each connector,

making sure to have the screw facing forward where I could access it to tighten.

I snapped on the harness, positioned the clamps where I estimated the tips of the glow-plugs to be and tightened the clamps almost to the point of stripping them.

NO MORE GP CODES!!!
(It's been like this for years)
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
How hard is the material on the end of the glow plug where you added the threads?
I'm a bit late seeing this post, but in case Search ever leads someone back here, the terminals appear to be nickle-plated brass, so they thread easily. Having said that, it's important to grab the base of the terminal (I used needle-nosed Vice-grips) or it may twist off. Practicing on an old plug taught me a couple things. :D
 
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