Ignition electrics problems Ballast Resistor

cedar said

That's the best way, rip it all out and start from scratch. Its possible that VW still do that resistance wire, might be worth a phone call.  Cheers.

I'm going to investigate into whether or not I'm meant to have an in-line ballast resistor, or if my model just has a resistive wire, I'm sure I read somewhere that the relay is responsible for controling the voltage, I'll report if I figure out where I saw that.

I saw these two bits of info on relays which makes me think the relief relay is responsible for controlling the current to the coil, though whilst I'm re wiring I will look for any trace of an in-line ballast resistor.

Relays

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism, but other operating principles are also used. Relays find applications where it is necessary to control a circuit by a low-power signal, or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. Relays found extensive use in telephone exchanges and early computers to perform logical operations. A type of relay that can handle the high power required to directly drive an electric motor is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device triggered by light to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protection relays".

What it probably does is have a 1 Ohm load connected to the X Relay circuit, which switches off when cranking, I believe. Plus an ordinary 12v from the IGN.

Which means its probably been wired wrong, still dont know why you'd need a ballast resistor, as that doesnt really do anything other than lag the current drawing (ie 90 degrees out of phase) when coupled with the condensor, unless its some power phase related thing.

Return it to how it should be in Haynes is a good idea at any rate, 1OHM load or resistance wire, makes no difference as long as both are rated accordingly.

I'm hoping to do the re-wire this weekend, so I'll let you guys know how it goes, thanks for all the comments and advice.

Have a look at this resistance wire, it may be totally inappropriate, an element for a cheese cutter or something, but it could be just what you need.
http://cgi.ebay.co.uk/1xM-CONSTANTAN-RESISTANCE-WIRE-20SWG-0-9mm-0-75-Ohm-m_W0QQitemZ110496694609QQcmdZViewItemQQptZUK_BOI_Electrical_Components_Supplies_ET?hash=item19ba1dc151
The seller would be able to tell you. If you used 1200mm it would give a resistance of 0.9ohms which is about right. Heat, insulation, and mechanical strength would be the concerns.

The relief relay looks like its something to do with the lights to me and is slotted in the front of the panel with the others so the one you've found is an extra that has probably been put in by a previous owner. I would take the whole lot out.

Check that the coil primary has a resistance of 2ohms, or near as, and if you want to measure the voltage at the coil it must be in circuit with the points closed, ie its energised. You won't get a belt off it unless you flick the points open, even then you'd have to be touching the HT side.

Cheers.

Cheers for the link,

I'll ask my dad if the stuff they use at his place is resistive car loom wire (it should be as they make car looms), so I'll get the 0.5mm white/lilac ballast wire etc from him and once fitted I'll test the required Volts Amps Resistance etc to check it's all working properly.

Cheers again I'll post any updates.

Cedar: You can and will still get a belt of the LT side, especially if the condensor isnt working, hence the large spark, thats what the condensor does, suppres the voltage.

From memory I think  1kv will jump 10mm, so go ahead hold that LT side bud

I don't think you can get any more than 12V or so from the low tension side, its the HT side you get the kick from. As far as I know the 12V energises the primary and its when the points open and that voltage collapses that the high voltage is induced in the secondary, that then jumps the gap at the plug to earth. You don't want to get anywhere near that with the engine cranking or running. The condensor does stop the points from arcing but how it does it I don't know.
Cheers.

It looks like some of the extra wires are to do with the immobiliser fitted by a previous owner.

I'm hoping to look at it tomorrow, I'll keep a record of where the immobiliser wires are going to in case I want to wire it back in after the initial re-wire.