MKIV Ignition Coil Wiring Harness Replacement ---- DIY

[TheAnswer#3]

can anyone find me a link of a good ignition coil wiring harness

[Henni]

To buy?

Here:
You want the top one for the selection from germanautoparts.
http://www.germanautoparts.com/Volks...ectrical/455/1


http://www.ecstuning.com/Volkswagen-...arness/ES7679/

[Henni]

could the wiring harness being cracked cause the 4 fuel injectors being short to ground? i have cracks on my wiring harness and i have a new one to replace it but not the tools.
I really dont feel like messing something up


VCDS-Lite Version: Release 1.1
Tuesday, 03 April 2012, 15:10:42:56075


Chassis Type: 9M - VW Jetta IV
Scan: 01,02,03,08,15,16,17,19,22,29,35,36,37,39,46,47,55 ,56,57,75,76

-------------------------------------------------------------------------------
Address 01: Engine Labels: 06A-906-032-AWW.LBL
Controller: 06A 906 032 DL
Component: 1.8L R4/5VT G01 0003
Coding: 07500
Shop #: WSC 00066
VCID: 6BA99FA40A8B
10 Faults Found:
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -
17964 - Charge Pressure Control: Negative Deviation
P1556 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
16686 - Cylinder 2: Misfire Detected
P0302 - 35-10 - - - Intermittent
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
17633 - Fuel Injector for Cylinder 1 (N30): Short to Ground
P1225 - 35-10 - - - Intermittent
17635 - Fuel Injector for Cylinder 3 (N32): Short to Ground
P1227 - 35-10 - - - Intermittent
17636 - Fuel Injector for Cylinder 4 (N33): Short to Ground
P1228 - 35-10 - - - Intermittent
17634 - Fuel Injector for Cylinder 2 (N31): Short to Ground
P1226 - 35-10 - - - Intermittent
Readiness: 0000 0000

W/ the failure to ground I have seen this be the fuel pump relay to cause this problem. A friend of mine had the same thing happen, I replaced the fuel pump relay and that fixed the problem. The harness can cause that also.

[warranty225cpe]

Alright. This is what I did. (Sorry if this is a bad write up, I have had a long day)
I got rid of the relay box next to the "waterfall".
This:

Split apart:

What you need to do is remove the top of the relay box. What you will find on the inside are two relays. I am a fan of not destroying what I am removing, just in case I want to be able to put it back. On the side of the relay box (where the wires come through to the relays) there is a rubber piece that will slide out. Remove that w/ the relay tray. Once the relay tray is out, look on the sides of each relay. There are two tabs. I removed one relay at a time so I wouldn't mix them up.
Once you remove one of the relays split the tabs on the side of the plug and it will fall out.
In this pic my fingers are pointing to each tab.

Open them up and the plug drops out. Do this to each. What I did was put some grease on the connections and then wrap up each relay w/ electrical tape. Putting grease on the connections will help against any water or condensation on the contacts.
It should look like this:

I took an x-acto knife to the rubber piece w/ the wires going through it inorder to be able to slide it down the wires. Be careful when doing this due to the wires underneath.

Slide the rubber piece back a bit along the wires. Now you are ready to put the relays in the "waterfall".


From here on out all you have to do is figure out how to place them inside the "waterfall" so the top cover snaps shut.
This is how mine looked when I was fitting them in.


and the end product.

Sorry for such a crappy write up. I hope it helps out.

Thanks for the write up. I'll be doing this today so I can free up some room for my catch can.
For you sir

[jmkyler3]

I may be doing this today. Have the harness but gathering the correct tools and waiting to see what mother nature has in store....


Seeing my car is a 2000 model with the automatic, I am assuming the 2001 edit should do?

[jmkyler3]

I may be doing this today. Have the harness but gathering the correct tools and waiting to see what mother nature has in store....


Seeing my car is a 2000 model with the automatic, I am assuming the 2001 edit should do?

So I have all of the pins done and ready to swap in the new harness but one major question has me puzzled:

The new harness I bought from GAP: the 102 wire is purple with a black stripe
The old harness: the 102 wire is black with a blue stripe

Man, should I gamble here and just do it

[toby lawrence]

So I have all of the pins done and ready to swap in the new harness but one major question has me puzzled:

The new harness I bought from GAP: the 102 wire is purple with a black stripe
The old harness: the 102 wire is black with a blue stripe

Man, should I gamble here and just do it

Do you have a Bentley? Wiring diagrams = mucho importante.

[jmkyler3]

Do you have a Bentley? Wiring diagrams = mucho importante.

Yes sir, got that.

The gamble paid off as it works like it did before (While explaining it to a mechanic friend, the light went on in my head. The color of the wire on the replacement harness really didn't matter so much as long as it was going into the correct place on the ECU. I did cover my ass by tracing the wire in question from the ECU to the old harness.)

Over all this wasn't a hard project, yes the pins on the front connector were a PITA but doable. The paper clip worked fine on the larger pin while I used bent baby pins for the little pins.

[Slimjimmn]

I spliced my 8 wires at instead of re-pinning the connectors.
Worked great!

[Madein_USSR]

Does any one know where to get the actual pins for this pin connector, i a f*d mine when removing
i am lookin for the male pins

[Slimjimmn]

Dealer only. I just threw mine in the trashthis morning

[cjb88]

So I've read through this whole thread, and I am just wondering: While so many people deem it necessary to replace the entire harness all the way to the ECU, is it really necessary since the overheating/melting/cracking issues doesn't go much past the head? Both INA and 034 make a short harness that allows you to add a connector just next to the head, maybe 6-8" into the harness. Since those harness are CRAZY expensive, what about just taking the OE replacement harness and soldering it in? I'm not concerned about either the resistance in the harness after soldering or the quality of work as I've done tons of electrical work. I just don't have the time to do this repair "the right way" especially since it doesn't seem totally essential. Thoughts?

[groggory]

So I've read through this whole thread, and I am just wondering: While so many people deem it necessary to replace the entire harness all the way to the ECU, is it really necessary since the overheating/melting/cracking issues doesn't go much past the head? Both INA and 034 make a short harness that allows you to add a connector just next to the head, maybe 6-8" into the harness. Since those harness are CRAZY expensive, what about just taking the OE replacement harness and soldering it in? I'm not concerned about either the resistance in the harness after soldering or the quality of work as I've done tons of electrical work. I just don't have the time to do this repair "the right way" especially since it doesn't seem totally essential. Thoughts?

I think that solution is fine assuming a few things...

1) You use both mechanical + solder in your technique. AKA, if the solder were to go soft due to some high temps, would your mechanical connection still hold it together? This is a typical requirement for soldering stuff in an under-hood application.

2) You use heat shrink on each wire that is designed for oil, chemical vapors and won't break down. Then double heat shrink the whole thing together

3) You ensure you don't have ANY bending at the location you're doing the soldering.

4) You ensure that corrosion cannot become a problem. AKA. Wire plugs or some other method.
...

This is a lot of IF's. These are very important wires and your aptitude is the key ingredient in it being made correctly.

Those aftermarket harnesses are expensive because they are using proper high temp, chemical resistant, high quality wire, heat shrink, abrasion sleeving, connectors, and environmental sealing. Plus they're being made by hand in low volume, so they are expensive almost custom solutions.

People use the OEM parallel solution because it is cheap, works great, and doesn't add any extra point of failures to the system.

[Slimjimmn]

Solder is for electronic boards, chips, ect. I guarantee anyone $100 I can tear apart any soldered/heat shrink wires you put together. (and i'm no ufc fighter either haha)

The one and only proper way to join 2 wires is this:
http://www.shop3m.com/3m-scotchlok-s...connector.html

Auto parts stores sell them in packs of 25 (red ones for 18-22awg) of non 3m brand. they work just fine, but have a little less sheating on them so if you crimp with the incorrect tool it will break the seal.

I did this on my car this weekend and its good to go. Spliced the wires in the black plastic shroud by the brake resivour, and the 3 wires at the VSS to body harness plug.
The OEM updated harness uses the high quality teflon/nylon wire covering not the usual plastic/rubber/flexy cover usually used on wires. Its heavy duty, just like the INA kit.

[groggory]

Those are excellent connectors.

[Slimjimmn]

Those are excellent connectors.

[toby lawrence]

Soldering is fine, but it's just not as good of a connection. Crimping is more likely to yield you a good connection that will last. Soldering can be done improperly... both in terms of cold joints or adding too much solder that wicks into the conductor and then stiffens your wire up unnecessarily and you get premature stress failures.

.. or you could just do it the right way and run the new harness to your ECU connector and plug in the properly-crimped and brand-new terminals.

[cjb88]

.. or you could just do it the right way and run the new harness to your ECU connector and plug in the properly-crimped and brand-new terminals.

I understand that so many people consider "the right way" to do this repair is to replace the harness all the way back to the ECU, but how many people have actually found harness damage down the line in the harness? Yes, doing it another way besides the entire harness will take less time. Honestly, that's part of it's appeal because I simply don't have the time to potentially have my car down for a long time if I ran into any issues. I definitely agree with the "do it right the first time" mentality, but I'm not even seeing any physical damage on the harness right at the coils at this point so I find it pretty hard to believe that I would get any benefit from replacing it all the way to the ECU vs just past the VC as long as the connections are done properly. Whether it be the crimp connections like that or a short harness like the one from 034. Are the INA and 034 harnesses worth nearly $200? Anywhere else to get one from?

[groggory]

Are the INA and 034 harnesses worth nearly $200? Anywhere else to get one from?

They are the same harness. INA makes them.

Are they worth it. Hands down yes. I bet INA is down at least $75 in just materials making them. Then of course there is the labor ridden process of measuring, cutting, stripping, crimping, heat shrinking, and then QC'ing the whole assembly. It's a lot of work. Plus, it's low volume work. It's not like VW where they put in an order for 10,000 to be made at once.

If you wanted to do an inline harness yourself you could, but you need to be careful to use the correct heat shrink butt connectors, abrasion sleeving, and secondary heat shrink throughout if you want to do it right.

The OEM inlay is a 100% solution.

The INA inline is a 100% solution.

The DIY inline is as good as you are willing to make it and your know how on proper wiring. This is an important bunch of wiring...so if you're gonna do it, make sure you do it right.

[cjb88]

Does INA not have a website that actually shows everything that they sell? Only website that I found just has contact info and nothing else. And I think probably what I'll end up doing is buying the short harness from either INA or 034. I could definitely build one myself, but by the time I buy new connectors, pins, proper colored-wires, sheathing, etc, it will be better spent to just buy one.

[groggory]

Does INA not have a website that actually shows everything that they sell? Only website that I found just has contact info and nothing else. And I think probably what I'll end up doing is buying the short harness from either INA or 034. I could definitely build one myself, but by the time I buy new connectors, pins, proper colored-wires, sheathing, etc, it will be better spent to just buy one.

Check out INA's facebook for all their stuff.

[Slimjimmn]

IMHO...

Don't waste money on the INA harness.
You can buy 3 VW harness' (they use the same high temp teflon coated wires) for the price of one INA harness kit. plus its basically plug/play compared to the ina where you have to "build" the second half of the harness.
And from all the harness' I have seen or fixed they are oil soaked to hell up to the driver side frame rail portion of wires.
Yes the wires right on the side of the valve cover are exposed to lots of heat as well, and oil, and they get brittle. Why not do one vw kit, (for 78.00) and be done forever. Plus then you dont have an ugly boxy connector on the side of the valve cover.

[cjb88]

And from all the harness' I have seen or fixed they are oil soaked to hell up to the driver side frame rail portion of wires.

How in the hell do the ignition wires soak up oil? I've seen pics of people's harnesses all crack and burned and stuff and mine doesn't look anything like that... at least all the parts that I can see. I'm more thinking of this along the lines of fixing/replacing it before it gets that bad. And my reason for not wanting to do the full harness all the way to the ECU is simply that #1- it doesn't seem like I have much damage to the harness at this point. #2- I don't have a lot of down time and I DEFINITELY cannot have the car down for any period of time.

[Slimjimmn]

oil leaks from cam chain tensioner and or valve covers.

My harness was wet with oil all the way to right above the starter.

I spliced in the new harness in the black plastic shroud area next to the brake resivour/relay bracket.

The new updated vw harness wires are covered by teflon coating which will not soak up chemicals and is very strong resistance to heat.

[BassNotes]

The PO of my car (and/or the shop he used) loved butt splices but didn't know how or where to use them. I found them all over in various states of disrepair and disintegration. Many were intermittent, inappropriately small, poorly crimped, corroded, high in resistance, etc. I got rid of all that I could find, usually replacing them with a Western Union splice



which I sometimes added a little solder to for stability and to preserve the connection. My favored wrap for the splice is Scotch 23 splicing tape, especially in locations that are exposed to elements, because it can seal to itself extremely well.

[WolfsburgNate]

I have no idea why anyone would even want to splice in the new harness. It seems like so much more work to find every single wire, cut them, make sure its the right length, strip them, crimp them, solder them and you still run into the chance for human error. Especially if you removed the old harness all the way back to the wireway by the brake resevoir?. Why not just go the extra 3 inches and just do it correctly and save a ****load of time and energy. You guys are crazy.

[BassNotes]

I have no idea why anyone would even want to splice in the new harness. It seems like so much more work to find every single wire, cut them, make sure its the right length, strip them, crimp them, solder them and you still run into the chance for human error. Especially if you removed the old harness all the way back to the wireway by the brake resevoir?. Why not just go the extra 3 inches and just do it correctly and save a ****load of time and energy. You guys are crazy.

Unless you don't have suitable tools for popping the pins out.

[Slimjimmn]

Unless you don't have suitable tools for popping the pins out.

Which are $90.

[cjb88]

Any cheaper place for these tools? Maybe someone willing to rent them when I get to the point when I do this? Yes, I guess this means I will probably end up doing the full harness. My cam tensioner seals are leaking pretty bad. :-(

[BassNotes]

Which are $90.

Unless you get them for less. I think my set cost about $40.

[cjb88]

Unless you get them for less. I think my set cost about $40.

Where did you get yours from?

[Slimjimmn]

People get these kits but Ihave seen them in person and they are so tiny its hard to hold to remove the pins from the terminals of the connector in some instances.

http://www.ebay.com/itm/VW-Audi-Conn...b4e4f5&vxp=mtr


This is another kit made by schwaben in germany. Works great, but they are kinda flimsy imo.
http://store.blackforestindustries.c...2piuntere.html

I have this one:
http://vw.snapon.com/SpecialToolsDet...temid=33530028
and this one:
http://vw.snapon.com/SpecialToolsDet...temid=33370028
and this one:
http://vw.snapon.com/SpecialToolsDet...temid=33340028

all oem vw tools. It covers most all the usual terminals in vw cars.

[BassNotes]

Where did you get yours from?

It's a Schwaben kit from ECS, several years ago. I think they had it featured on sale, so I jumped at the opportunity.

[theswoleguy]

subscribed

[WolfsburgNate]

Which are $90.

http://www.amazon.com/Stanley-66-039...rs+screwdriver

Not quite $90. I spent about 45 seconds total depinning wires while replacing this harness just using the smallest flat head screwdriver I could find. Just shove the ****er in the slot as far as it will go on both sides, and the pin comes out every time. Never broke anything doing it this way either. People on here do not know how to improvise.

Anyone trying to do this don't listen to the people that say you need to spend all of your money on some stupid "tool set" for depinning. I don't even know where to begin explaining how unnecessary it is.