Quest for originality; Cable wiring harness tape & PVC connectors?

[rsporsche]

@sfdon ... i think its time to open a bottle of BROSE ...

 

[eriknetherlands]

Time to tape this shut; i've ordered 4 rolls of Coroplast; it's a german company, so it is easily available in the Netherlands.

Let's see if what I get is matching to our e9's, as I saw that coroplast does make a lot of variants. Hope I get the right ones.
I'll update with a comparison and coroplast type number identification when recieve the rolls.

 

[eriknetherlands]

Update on the tape, as promised.

Pulled my harness out of the car and began stripping it. It actually looks very good. Even has a bmw parts label on it, at the fusebox so possibly the PO replaced it some time ago.
Anyhow, I've purchased the coroplast tape, and it works well I must say. It's as identical as I hoped for, and works easily.

About 1 meter done of the 25 in the car.
- Stripped old dirty tape.
- Inspect wires for broken insulation.
- Checked Ohm resistance to end
- Clean all wires 1 by one with acetone
- Retape with the cloroplast.

I found it the easiest to suspend the harness on a few hooks, and drape it like a curtain, main "trunk" being horizontal, hanging the branches vertical. It gives 360 access to spin the coroplast spool around it freely.

 

[eriknetherlands]

Just last week someone (who was that: I want to give a big thanks, as I otherwise wouldn't have found them) posted an image of a company's parts brochure for the pvc flat block connectors that are used in our coupes in various places.

Edit Feb 2022: here it is: thanks to @NWDBayArea :

Wiring Harness - Insulated Sleeves

Hello! I am looking to see if anyone has found a vendor that sells these insulated sleeves new. My hunt has been unsuccessful... Attached is a photo and screenshot from a parts catalog. Any information would be helpful! Thanks, Nick

e9coupe.com

I did some searching and it turns out these are still made in Germany, it even looks to be exactly identical, right down to the Brand HSU inside the diamond shape, the small ribs on the side and the small circle for pressing to release the female connector.

Company is called Hsu-kg. The parts are called "flachsteckverbinder".

If you follow this link, you arrive at their website. Below the table is a 15 mb brochure; download it and lookup page 14 you see the connectors listed.

Hans Simon OHG, insulation sleeves

On page 5 you also find the clear plastic isolation sleeves.

I'll contact them to see if I can buy them from Germany or through their dutch importer.

 

[stphers]

I would be quite interested if you can get these I need about 35-40 of these items

Thanks, Rick

 

[eriknetherlands]

I would be quite interested if you can get these I need about 35-40 of these items

Thanks, Rick

You mean the single connectors or the flat type ones with multiple sockets?

I'll post once I have some input.

 

[eriknetherlands]

The flat type connectors are indeed from the HSU-KG company. The harness on my car has their logo's on them.

I needed some thorough cleaning to see it however:
- Stick a screwdriver in from the Male (empty) end.
- Unclip a small hook.
- Pull out the female, with pliers if you don't trust the wires.
- soak and clean in solvent with a brush on the inside.

 

[stphers]

Yes, those are the ones The ones from Goodspeed come in batches of 4, easily cut apart for singles or doubles . They have been on B/O for over a year and no response by email, maybe they are not around anymore, too bad. If you get some bubbly bleach ( toilet bowl cleaner ) and soak those yellowed bits for a couple of weeks, a good part of the yellowing goes away , they don't come back white or clear but much much better Let me know if that company has them

Thanks, Rick

 

[Krzysztof]

The flat type connectors are indeed from the HSU-KG company. The harness on my car has their logo's on them.

I needed some thorough cleaning to see it however:
- Stick a screwdriver in from the Male (empty) end.
- Unclip a small hook.
- Pull out the female, with pliers if you don't trust the wires.
- soak and clean in solvent with a brush on the inside.

Update on the tape, as promised.

Pulled my harness out of the car and began stripping it. It actually looks very good. Even has a bmw parts label on it, at the fusebox so possibly the PO replaced it some time ago.
Anyhow, I've purchased the coroplast tape, and it works well I must say. It's as identical as I hoped for, and works easily.

About 1 meter done of the 25 in the car.
- Stripped old dirty tape.
- Inspect wires for broken insulation.
- Checked Ohm resistance to end
- Clean all wires 1 by one with acetone
- Retape with the cloroplast.

I found it the easiest to suspend the harness on a few hooks, and drape it like a curtain, main "trunk" being horizontal, hanging the branches vertical. It gives 360 access to spin the coroplast spool around it freely.

Great info Erik!

As the solvents are not the best for lungs and in general, I would suggest to use ultrasonic cleaner with heating option. They are really doing great job to clean sophisticated shapes. Maybe you have an access for one around. Save time, chemistry and health.

As engineer (as you Erik) I need to admit resistance test done by ohmmeter will not really provide sufficient quality judgement about the connector, wire and crimping quality.

Quite a good solution is to measure voltage drop across the wire carrying specific current.
Low current wires still are OK to be tested by DC Resistance but ones for lights etc are better to be checked under DC load. It can be bulb/reflector or resistor.

Additionally some of the wiring can be locally overheated. If the wire isolation is brittle or darker might be required to change it.

Some are re-wiring lights (Low Beam, Stop, Indicators, starter ...) to higher diameter (lower AWG) to decrease the losses on the wiring. It is normal the diameter of the wire used is a compromise efficienct/cost, so it can always by better but means drop of the originality which - I believe - is something you're bidding for with your E9.

 

[eriknetherlands]

@Krzysztof : Good tip on the ultrasound bath; it works wonders on the connectors especially.

 

[paul cain]

@eriknetherlands

I would steer clear of using the Tesa 'fuzzy' tape in the engine compartment. It won't survive the most basic of chemical assaults.

If you want something that is very close to what BMW used 48 years ago, I found that Scapa has a very close substitute. See attached. The dirty tape is original BMW Tape off of Patricia Mayer's car. On the right is Scapa's tape. We can buy Scapa via Amazon. It appears that their HQ is in Manchester UK. Other outlets are in the below image. HOpe this helps.

 

[HB Chris]

Scapa 167, Scapa 1810?

 

[eriknetherlands]

@paul cain : Thanks for your suggestions. I'll have a check. SFDon also suggested a high temp version from Tesa for the engine compartment. I wonder what their chemical resistance is; i"ll see if i can dig up a spec sheet.

regarding the Scapa tape: it indeed looks very similar. I've already purchased 5 rolls of the Coroplast which is also pretty close. Seeing your image of the Scapa tape I think it may be even closer to original.

 

[eriknetherlands]

@paul cain : Thanks for your suggestions. I'll have a check. SFDon also suggested a high temp version from Tesa for the engine compartment. I wonder what their chemical resistance is; i"ll see if i can dig up a spec sheet. .

Ordered some tesa 51036 high temp tape for the engine compartment. The spec sheet do not state anything on the chemical resistance, so I will give it some home tests with different solvents.

At least the Tesa 51036 tape is also a very good match to the original, compared to the coroplast.
The coroplast has just a tad more surface with short fibres, but it matches better in appearence as it has a weaving pattern that forms diamonds, like the original.
The original is a bit smoother then the coroplast, which is better matched by the Tesa, but the Tesa is a bit shiny and has lines running across it from the weaving instead of a diamond pattern.



In my pics the small roll is coroplast, the Large roll is Tesa 51036 high heat engine compartment compatible type.
Last pics next to a piece of original tape, still on my harness. Which was cleaned with solvent and dried.

I think if you put two cars next to each other, one with coroplast, the other with Tesa, I wouldn't be able to tell the difference. For me both pass my acceptance criteria, and I'll be using them both; coroplast as I already have ot for the interior, tesa 51036 for the engine comp harness.

In the end I think our blinkers don't really care about all of this....

 

[eriknetherlands]

Ordered some tesa 51036 high temp tape for the engine compartment. The spec sheet does not state anything on the chemical resistance, so I will give it some home tests with different solvents.
.../...

As @sfdon already mentioned, the Tesa is not good with solvents. A slight breeze with paint thinner will have the tape release itself. Even just some solvent vapors will release it already.
The Coroplast needs to be soaked in it to get loose.

So, if you use the 51036 TESA for the higher temp resistance in the engine compartment, be easy on paint thinner for cleaning grease /oil etc in the vicinity of it.

 

[eriknetherlands]

All 3 main harnesses now clean, will measure them up with resistance and for voltage drop while under load in the next weeks.

Funny thing: i found weld spatter inside the harness just at the fuse box.
PO has welded on the upper A pillar under the front fender, and this metal ball solidified inside the harness. Thankfully all strands look intact, but voltage drop testing will tell all.

 

[eriknetherlands]

Engine harness .
And an example of how I cleaned all connectors ultrasonically with paint solvent.
Just put a plastic container inside the tank filled with regular water. Works amazing, but as our wires have painted color markings on them, you can drown them only for a few seconds, otherwise they loose their paint colors & with that their identity.

I even have in my loom a thick brown earth wire, that after cleaning turned out to be brown paint on a red wire!

 

[eriknetherlands]

And lastly the smaller interior harness for the windows. It is layed out as in the car, looking from rear to front.
Left and right along the sill, and middle crossing in front of the seats and over the tunnel.

The second pic shows how much tape even comes from this smaller harness.
I've used a heat lamp to soften it up, it greatly reduces the effort to unpick the ends and start unwinding it. It's one sticky mess!

 

[Krzysztof]

Engine harness .
And an example of how I cleaned all connectors ultrasonically with paint solvent.
Just put a plastic container inside the tank filled with regular water. Works amazing, but as our wires have painted colour markings on them, you can drown them only for a few seconds, otherwise they loose their identity.

I even have a thick brown earth wire, that underneath the brown paint is just simply red.

Have you also tried other chemistry than pain thinner? Not sure how the paint thinner will impact overall isolation lifetime, even if it looks fine today.

I would probably start with isoprophanol (alcohol) or clean benzine which are not so aggressive.

 

[eriknetherlands]

Thanks @Krzysztof, I'll have a look into alcohol.
I did try with white spirit, but that didn't cut the grime as quickly as paint thinner.