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Rewire

Posted: Tue Apr 18, 2017 2:54 pm
by MarkK
Now that my car is almost totally stripped of everything I want to have it rewired before starting to build it up again. I have the new Autosparks loom and have considered doing it myself but I wonder if anyone could recommend somebody who could do this? I am not an expert and wiring scares me a bit!
Mark

Re: Rewire

Posted: Thu Apr 20, 2017 1:24 pm
by TonyG
Mark,

If you have the car stripped for restoration it is best to wait until most of the rebuild is complete before doing the wiring. Painting and fitting parts is easier without having cables to worry about. I restored my 12 last year and used an Autosparks loom. This was made more complicated because the loom was modified by Autosparks for flashing indicators and an alternator. As such, the wiring diagram in the workshop manual was only partly correct. However, assuming that yours is more standard, it is not too difficult to get the wiring sorted into the right places. The first thing to do is lay out on the floor the component parts of the loom you have bought. From memory, there will be a small set of wires for the dashboard clocks and switches, a main loom that goes from the dashboard to the fuse boxes and regulator box plus two other bits of loom that do the rear lights and front lights and horn. I seem to recall that I had to source the wires from the dip switch and horn to the junction box near the steering box. Then to make sense of this lot you will need to copy and enlarge the diagram from the manual and then identify each wire and label it. I did this with masking tape and noted what the wire was for and if it was, for example, the switch end or the fuse box end. All the wires are colour coded so it's just a matter of working through them. Once you know all this it's quite easy to lay the loom in place in the car ready to connect at the junction boxes, fuse boxes, switches and components. At this point you may feel confident enough to get the soldering iron out and start making the connections or, alternatively, engage an auto-electrician to do it. However, the job will be made easier and I assume cheaper, because the cables will be marked and in place.
I hope that helps a bit but I do recognise that it looks baffling to start with!

Tony.

Re: Rewire

Posted: Thu Apr 20, 2017 4:14 pm
by MarkK
Thanks for advice Tony. I bought this car two years ago when it had already been painted (really beautifully). The previous owner had not totally finished stripping it before he just gave up, but beautifully restored body. That is why I have stripped the last bits and want to start rebuilding with a rewire and engine work.

I restored a P4 about 15 years ago and did all the building up from scratch exactly as you suggest - it certainly is much easier! Then the rewire was one of the last things I did. Luckily I have no time constraints to finish it, so it might be finished in my retirement, another ten years.

Thanks again
Mark

Re: Rewire

Posted: Thu Apr 20, 2017 8:39 pm
by luli
The wiring begins at the instrument panel and continues from there on. It can not be finished unless the lights are on the wings and bumpers, the steering, dynamo and starter are in place, even the gearbox and brake rods, including petrol tank. Therefor I think Tony is right and wiring now is premature. See some pictures here: http://wp.me/pXLKy-1mm and here http://wp.me/pXLKy-XG. The pictures are high resolution; clicking on them will let you see the fine details.

Re: Rewire

Posted: Sat Apr 22, 2017 11:38 am
by TonyG
Mark,

Another thought that might be helpful; to get your car running and drivable while you undertake your long term rebuild it is quite simple to install temporary starting and ignition wiring circuits and this might provide you with what you need to get the engine up and running. I did this with mine after putting in the engine but before fitting the wings, bonnet etc so that removing the engine again would be simpler if a problem was identified.

You will need to get a local auto-electrician to make you a suitably long battery cable and end lugs to go from battery under rear seat to the starter solenoid. Also an earth cable for the battery and one for the engine. Then a cable to go from the other side of solenoid to the starter. A starter solenoid with a press button will also be needed. All these parts will be used when the car is wired properly so no duplication of effort. Also, none of these bits will have been included in loom unless you specified them.

Then, using regular size auto wire all you need is to do is put in the Low tension circuit from the battery feed at the solenoid to the coil via a switch and from the other side of coil to the distributor. If you are fitting an electric fuel pump this needs to be connected on the switched side of the ignition circuit before the coil.

Once done it is a matter of flicking the switch and pressing the solenoid button to start the engine.

I changed the polarity of my car during the rebuild to negative earth. No real need but conforms to modern thinking. The loom required is the same but the electric pump and alternator (Dynamator on my car) need to be negative earth type. Original gauges, sender units, wiper motor and starter are not polarity conscious. Some electric clocks probably are though. If using an old Dynamo this needs to be re-polarised by flicking the revised feed onto terminal, but suggest you research this on Internet or with Autoelectrian to avoid doing any damage.

Hope this option helps.

Tony.

Re: Rewire

Posted: Sun May 14, 2017 3:03 pm
by MarkK
Thank you Tony, very helpful. I think I will do this.