Replacing Wiring Harness--Can I do it myself?

[Van Scully]

Hi Vanafriends,

I'm trying to get my (new-to-me) Vanagon to run. We bought it, drove it for 15 minutes and then the engine cut out. It's done this a couple of times. In fact last night we towed it to a repair shop. Got there, tried to start it just to see. It started and we drove home. Then it died again on the way home. Go figure.

We think it's a problem with the wiring harness. We purchased a new one from Vanagain and it should arrive in a week or so.

My question is this: should I attempt to replace the harness myself? My husband and I are reasonably smart people (though our parents would beg to differ after hearing we bought a 30 year old van ) so between the two of us, is it possible? Or should I just let the mechanic do it? Also, how long would it take a mechanic to do something like this? He quoted us at $1400 parts and labor. We bought the harness ourselves for $800.

Anyways, if anyone has some feedback or advice, I'm all ears.

Thanks!

[Vanagon Nut]

What year and fuel type is your Vanagon?

If the Vanagon is old, high miles, treated poorly over the years, driven in salty road conditions, may have suffered a partial engine bay fire etc. replacing the harness isn't such a bad idea from a "restoration" or "preemptive strike cover all your bases" stand point but......

the stalling issue could be due to one or more factors not directly related to the wiring harness.

Do you have a Bentley manual?
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1981 Westy DIY 15º ABA
(VW Gas I4)

1988 Westy DIY 50º ABA

VE7TBN

[PDXWesty]

I just had my fuel injection wiring harness replaced in a shop. The labor was probably about 6 hours and they charged me $150 for a used verified harness. I didn't know new harnesses were available or I may have done that.

It's probably not a complicated job but it will be time consuming. I'm not sure if you need to completely remove the old before installing the new, but the danger is not remembering how and where everything goes. If you do this yourself, I would take abut a 100 pictures of the routing before you remove the old to document where everything goes.

I had the same problem with the engine cutting out and it actually turned out to be the ECU. My old harness was hacked up so that's why it was replaced, just as insurance.

The benefit of having a shop do it is if there are problems, they will need to rectify them instead of you having to try and figure it out.
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89 Westy 2.1 Auto

[16CVs]

A relatively simple job for a mid level weekend warrior. The wires only go in one place.
I would worry more about where they are tied down to the chassis then where they go.
There are some plastic wire holders which can be opened and re used with a little bit of patience, Avoid cutting them if possible. The generic Ty wraps are no big deal, if you do not keep Ty wraps in your arsenal then go and buy quality commercial rated Ty wraps in Black.
The injector wires do not matter which injector they are hooked to. Everything else just falls in to place. I have a new harness in mine and it got rid of the pesky little gremlins that used to show up. Money well spent in my book.
My guess would be about 3-5 hrs start to finish,

Stacy
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1987 Syncro Westfalia Triple knob (bastard)
1989 Syncro Tristar Triple knob "Swedish"
2013 Jetta Hybrid a true "Zwitter"
Samba member # 14980
Call anytime number 650 722 4914 .
Keep Your van running and upkept tastefully for the love of the hobby.
Don't let your van end up in an "abortions" thread.

[Gauche1968]

[Steve M.]

Are you talking about the complete harness? For $800.00 I am assuming it is a whole harness. It is not money wasted.
I say this because there are sub-harnesses which taken together make the entire harness.

For example: in the engine compartment there is the Engine Harness, but also the lighting harness for all the rear lights.
As there is a separate harness for the front lights,
A harness for the instrument cluster,
A harness for the radiator fan, the harness for the air conditioning relay to operate the radiator fan as well.
There are more as well depending on what features your Vanagon has.

These sub-harnesses are not completely separate from each other. There is one or more wires going from one harness to the connectors to the other sections for the power. So effectively it is all one big harness, but it is the sub-harnesses together which make it.

So if you can find out which part of the harness it is you would save yourself a lot of work.

If you start this have a full charge on your smartphone batteries to take a lot of pictures before you disconnect everything.
Get a roll of blue masking tape and new SHARPIE permanent marker with good point to write in fine letters on the connectors to ID them.
mark everything because you can get overwhelmed by the confusion of wires everywhere!
Get a notepad and take notes!

Have you got a Bentley Manual? it would help answer questions your going to have about the wiring.

A good voltmeter would help you a lot if diagnosing what is going on.

Take a look at my thread where I am just getting into the harness on my Syncro.
https://www.thesamba.com/vw/forum/viewtopic.php?t=661562&start=20

Post some pictures before you start as people can see and advise you on parts of it.

As 16CV said it might be something which is not your wire harness so before you jump into the harness give us more details about the problem.
I know you described it, but there is always something else that can be said.

Do some searching here in the forum and take notes on what you find.
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This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[davideric9]

I think you can do this. Worth a try. Worst case is have it towed to the shop if you start and are unable to complete the work. I've taken on a few projects with this in mind. Gives me the confidence to jump in and so far I've never need to have the van towed in.
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1987 Syncro Westfalia, stock (bought 1994)
1986 Syncro Westfalia SVX, 3 knob (bought 2008)
1987 Westfalia (bought 2010)
1988 Wolfsburg GL (bought 2012)

[IdahoDoug]

I think it's doable by you, however, I'm puzzled at your diagnosis of "replacing a bunch of wires" to fix this issue. I'm not convinced that was the correct route to go.

To me, before disconnecting massive numbers of 30 year old connections and wires, I'd want the fault identified. Once you do all this disconnecting and such, you run the odds that will CREATE an issue on an old vehicle like this. it's much easier when it won't start to FIND the problem. You may put it all back together again only to find the issue is still there. And it was your $200 CPU that could have been replaced in 30 minutes with a sandwich in one hand.

In other words, you should have discovered Samba BEFORE choosing your repair route! Heh......

Doug
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1993 Toyota LandCruiser, 2002 BMW 325iX, 1982 Toyota Sunrader

[Van Scully]

Thanks for the encouragement and all the great advice.

It's an 87 gas Vanagon. A little more information as to why I think it's the wiring. When it died the first time we towed it to a shop and the guy looked at it and said he thought it was a wiring problem, but that he wasn't sure how to fix it since he wasn't a Westy expert. We then took it to another shop and the guy at first said we should replace it all since the wires were looking pretty shoddy. Then he called back and said he found the problem and just fixed one wire (I need to talk to him about the specific wire but he is out of town). We were able to drive it home but then it wouldn't start the next day.

Since both mechanics thought there was a wiring problem, we decided to replace the whole thing -- with the goal to get the van to be a lot more reliable.

We are replacing the fuel injection wiring harness. Here's a link to where we purchased it: https://www.vanagain.com/shop/wiring-harness-for-engine-compartment-86-92-vanagon/

[MrBuelterman]

I had a very similar problem, and it ended up that my ECU was going bad. An easy test is to start the van and then go tap on the ECU. It might not be the problem but its a quick and easy test.
Good luck finding your issue.
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86 2.4L 2WD Peloquin Westy

[Vanagon Nut]

[Steve M.]

[PDXWesty]

$1400 was parts and labor. $600 labor is about right for that job with overhead and warranty.
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89 Westy 2.1 Auto

[Steve M.]

[IdahoDoug]

Wow Steve - very very thorough and well written post about how to do this. Great advice from start to finish.

To the OP. Nothing in your reply would lead me to say "replace all your EFI wiring" Nothing. I think you should ignore for the moment you just wrote a large check for a wiring harness and use the Samba to diagnose the issue.

I will go further out on a limb and agree with Steve M's offhand comment about the $9 electrical part of the ignition switch that is cause for the largest % of no starts on Vanagons being your issue.

I'm not saying "don't install the wiring harness", only that you should discover what your real issue is before doing it. And you should not only know what wire some guy "fixed" for you, you should go over there and have him point to the wire, and to the repair he did.

Doug
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1993 Toyota LandCruiser, 2002 BMW 325iX, 1982 Toyota Sunrader

[Steve M.]

Thanks Doug!

Going off topic here, but it needs to be said since this is a new vehicle for you.
Actually your Vanagon not starting is a good thing!
Something else Van Sully you need to do is the Fuel Lines, perhaps more important then your no start issue right now! If it don't start it don't burn.

https://www.thesamba.com/vw/forum/viewtopic.php?t=440675&highlight=fuel+lines

http://www.benplace.com/fuel_line.htm

They are rubber hoses that if not replaced are probably worn with age and they are the #1 source of fire (#2 being electrical systems). They need to be replaced with the proper high pressure ethanol fuel rated hoses.
http://www.van-cafe.com/page_499_736/fuel-line-replacement-kit

Yes, your parents were right-it is a 30 yr. old vehicle. There is a lot of negativity from some people about them, but much more good feelings about them and experiences from people who own them!
_________________
This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[skills@eurocarsplus]

[Steve M.]

[Abscate]

The pricing is totally in line for a shop. Six hours to put it in is a good estimate, as opposed to a not-to-exceed-quote, which means it could be more if they run into problems.

I do think you want to get it running first, so you can carve out issues from the wiring harness job that may arise from your current problem.

Skills' note made me giggle because I just had this conversation with CFO last week...

Me: Scope of work is to cover identification and completion of these proposed items or 3 months, first occurring.

CFO: I want the contract to cover all items identified and not to exceed.

Me: In that case, I can promise you I will only find 3 months work of items to work on. Will that work?

CEO: Let me handle this, CFO.
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[PDXWesty]