Newbie Electrical Troubleshooting Questions
 

G'day gang,

I've just finished rebuilding my engine, my transmission is off at the shop getting the final parts of rebuild completed that I didn't have the tools to do myself at home. I'm now looking at the horrible wiring situation that is happening in the front luggage compartment and behind the dash. (1983 911 - Japan import)

The PO converted the car from LHD to RHD. Obviously a lot of electrics have to get switch over when doing a conversion. Unfortunately, he didn't do the best job of it and it was also incomplete.

Some obvious things that I need to fix are:

• Get all dash lights working - None currently work
• High beam indicator globe (blue light)
• Find a home for the blinking globe that I found behind the dash (I believe this is a Japan only EX globe that relates to the CAT system)
• Install side power mirrors. (A new harness was installed already just needs to be hooked up)
• Find homes for loose wires in frunk that aren't plugged into anything.
• Find out why interior light doesn't turn on when doors opened
• Get handbrake / seatbelt lights working
• probably lots more fun that I haven't found yet

I have a electrical probe tool where you can throw out power to a device and also test if it's earth or ground and a multimeter.

My first question is - I'm wondering if the fact that the side mirrors aren't installed could be the reason why some of the other electrics aren't working at the moment - eg. dash lights? At this point I'm terrible at reading wiring diagrams, but am working from the Bentley ones.

I'm also VAGUELY considering getting a new wiring harness and starting from scratch. Need to research that a bit more first. Any recommendations on who makes the best harnesses that don't cost as much as the car itself? :)

For a harness, reach out to Timmy2 here.

Spend time learning the diagrams. If you can blow them up to a larger size to improve the readability (11" x 17" or 22" x 34").

Hopefully the factory color coding is intact. You can then follow the circuits and verify they are intact. Most are independent of each other.

It is tedious but not hard.

I second the timmy2 recommendation. A new harness in the correct colors will make it much easier then trying to figure out what someone did in the past.
Plus it’ll look purty.
It sounds like you’ve invested in doing things right to this point I wouldnt skimp now.
Tony

+3 for Timmy2. Dennis is a great guy and easy to work with. He can make what you need.
He did some custom work for me. Beautiful. And lots of ID tags so you don't screw up.

Thanks for the referral to Timmy2, I will shoot him a message tonight.

Here's the fun that I'm dealing with:

https://lh3.googleusercontent.com/82...=w984-h1310-no

Oy

Looks like a left hand harness spliced into a RHD dash harness with numerous multi pin connectors.
What could go wrong...

I replied to your email, don’t know if the replacement harness is more $$ than the car, depends on what You paid.... :)

geez

Haha, imagine how I feel!

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So, due to budget constraints and the Porsche fund being practically empty since I rebuilt the engine and transmission, it looks like I'll be working with the wiring that's in there. I also still have to replace the soft top and have the rhd conversion engineer certified. Ugh.
I'll post my progress pics here and cries for help too.

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Good lord look a that wiring.

It will help if you can source the same factory color-coded wire to splice and continue the circuit to its target location. Either that or apply ID tags onto each wire, perhaps with the assigned color code.

Sherwood

Good tip! Thanks.
I had a look on the weekend and I noticed that the brown wire on one side of the connector isn't continued through the same spot on the other side of the connector. I know it's not a factory one, but wouldn't it make sense to continue to it? https://uploads.tapatalk-cdn.com/201...1ca2a1d177.jpg

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I would assume the person that did the conversion did not have the 100’or so different wire size and color combinations on hand.
Likely made their own wire map up with what they had...

Just some of my wire assortment.
http://forums.pelicanparts.com/uploa...1570479284.jpg

If those circuits function as designed, it'd be fairly easy to continue the factory wiring from the left half of that connector and substitute the correct color in the right half to its destination. Sourcing factory wiring is the next challenge. Short of having a similar car to cannibalize or a good relationship with Timmy2, there are a few internet sources that specialize in multi-color automotive wire.

Sherwood

You need to check the wiring diagrams since for some reasons, occasionaly the wire color will change at the connector.

Need wire, try Eagle Day (https://eagleday.stores.yahoo.net/elparandtool.html).

As he is in Australia, I doubt he will order from Eagle fray or me.
Shipping and duty is a killer there.
I’m sure there are more local sources for striped wires he can find.

Ah... didn't catch that.

Yeah, the exchange on the dollar, plus what I mentioned above is what is driving him to DIY it.
Lol, just looked at my last post, Day was autocorrected to fray...

He-he. :D:rolleyes:

He shouldn't get pinged for duty. I think you can declare at least a $1000 AUD of value and you'll be fine. The shipping will probably be about $75 to $100 US each way. I wouldn't imagine anyone other than timmy2 doing that wiring. Do yourself a favor and just have timmy2 do you a section of harness at a time. The savings in grief will be worth the investment alone.

Yes. Thanks. Use the factory wiring diagram as a road map to duplicate (as much as possible).

Jeepers! 100 different colour wires! I would never have expected that the car had so many!

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Things have changed mate and there is no $1000 threshold where you don't get charged duty. I would get stung on conversion rates, GST and import duty, plus shipping. If I was paying a US person in USD, the cost is quite reasonable. After all the additional costs, it adds up to money I don't have at the moment. See post #1.

I have to mention that most things that I have tinkered with in the car so far seem to work just fine. There are some dash lights that don't work which I suspect may also have something to do with the side mirrors not being connected and other bits not connected up just yet. If I can get every thing working for the time being, then that will be fine. I can look at re wiring once the Porsche fund has been topped up and the car is running.

I pulled out all of the horrible plastic wire wrap that was in the car. Such an improvement already. Hahaha

https://uploads.tapatalk-cdn.com/201...9dea5bb878.jpg

I rebuilt an engine with no experience, rebuilt a transmission with no experience (but some help from a pro), im sure I can have a go at this and learn a lot in the process.

Now, back to my newbie questions. What harness wrap is best to neaten this mess up?

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Wow! That is a lot of Red wires!

I would recommend as you trace them, you label them with the starting and ending points for future reference. Some thing like:
Fuse 6 to Left Headlight; or
F6 to L1 (using the codes from the wiring diagram)

A quick look at Amazon shows several options. In my opinion, The tapes and braids look the most professional. The spiral wrap and split tubing is easy to use. Tie wraps are effective and easy but, at times, can look amateurish. In the end, I would defer to Dennis on this topic.

I’ve been using techflex on wiring. Another idea is to use color coded heat shrink. You can get clear for protecting labels.

I’d suggest labeling your wiring with the naming convention used on the factory diagrams even if you don’t have the proper colors so you can match them up easier and avoid confusing yourself down the road when you forgot what this or that meant.

Use anything suggested for wrapping up the mess.
Labels are very important.
Looking at the recent photo makes the original split loom look good!

Awesome! Great tips, thanks! I'll go out and buy a label machine this weekend.

Thought I'd try something easy and work out why the front right indicator wasn't working. Opened it up and found this. Lots of white oxidation or corrosion (?) I assume. It's rock hard and super hard to remove. Its all over the housing and connections. The globe was cemented in with this stuff. I had to smash it and pull it out with pliers. I cleaned it up and managed to get it working again but it's a bit hit and miss. Needs a proper clean. Wire brush on drill didn't work too well.

https://uploads.tapatalk-cdn.com/201...636649fc1e.jpghttps://uploads.tapatalk-cdn.com/201...6ef47d919a.jpghttps://uploads.tapatalk-cdn.com/201...d8d021b723.jpghttps://uploads.tapatalk-cdn.com/201...63888dde51.jpghttps://uploads.tapatalk-cdn.com/201...695e26bc9e.jpg

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Is it possible the car came from someplace where they use road salt in the winter?

It's a Japan car. I havent heard of them using salt in all the years I've been there in winter. I think I researched it as well and found they don't use salt.

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IMO; Calcium Carbonate deposits from being by the ocean
soak in vinegar, clean with wire brush

Huh. It looks odd. Only other thing I can think of is the kind of corrosion that comes from exposure to salt air.

Edit: Ted beat me to it.

Also in the ignition box.
Funny, because I'm yet to find a single piece of rust on the car. Maybe it went for a swim at some point?https://uploads.tapatalk-cdn.com/201...6e7189fa0f.jpg

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Tsunami car?

Those low voltage circuit traces are the part most affected.
Next would be the termination points and the connectors.
Would advise identifying each functional block of circuitry with its associated wiring and approach in that type of focused manner.
The process of functional block elimination will allow the process to go faster after the first couple of hurdles.

I did this on a 35 ft boat with lots of electronic and electrical stuff, a 14 ft car is possible also.
Shout out to ORVAC electronics for parts support

On the weekend, I did a quick whip around the frunk and put yellow tape on all the unconnected wires and wires that were joined poorly and needed attention. There was a lot of yellow!

Also thought I'd have a go at installing the side mirrors. I took the switch apart and gave it a clean out. Connected all the wires up to their matching colours in the new harness and it works! The only thing I wasn't sure about was the two brown wires. Will need to research further.
https://uploads.tapatalk-cdn.com/201...aec01170bc.jpghttps://uploads.tapatalk-cdn.com/201...911918e1c8.jpg

Also, does most of the wiring when complete, live behind the blower box? I assume I should be removing that so I can work on the wires behind it and then route them behind there once complete?

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Yes, most of the wiring lives behind the blower box. I actually happen to have mine out right now so I’ll snap some pics for you later today.

You sir, are awesome! Thanks so much!!

Something else I wanted to ask everybody. What is the best option for crimping connectors? The last guy used the squeezy plier type and it looks super dodge and like they won't hold for very long. Any other options?

Also, this little wire junction box thing seems a bit average and the copper wire seems a bit exposed for my liking. Any better options for those? https://uploads.tapatalk-cdn.com/201...68ec5ad9bc.jpghttps://uploads.tapatalk-cdn.com/201...178f61fc32.jpghttps://uploads.tapatalk-cdn.com/201...bfb8f76690.jpg

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I use these and then solder the critical joints. Be sure the wire is fully seated and the crimps are tight.

Those are actually very good connectors. I used to work at an airport and we require the use of those for connectors in place of wire nuts or crimps in our life safety systems. The wire need to be trimmed so they are fully covered by the insulator and not mangled inside the connector.

Non insulated butt splices installed with the correct compression crimper and heat shrink is best for the singles. Solder the ends or install ferrules (again with correct tool) on the terminal wire ends and trim to fit properly as Harry mentioned. The copper strands compressed alone will eventually fatigue, break and come loose from the terminal.