Anything and everything Herald. Talk about anything from the first 948s to the last 13/60s.

Hi, I have bought an Aldon electronic ignition kit for my 1964 Herald 1200 estate. After reading the instructions which stated that the black wire is connected to the negative terminal on the coil and the red wire is connected to positive terminal on the coil I came across a problem. The positive terminal on the coil has a whitish colour wire connected on the bottom terminal (which I think has something to do with the stop light switch) while the top terminal has a green wire which is from the D-Type overdrive gearbox. Unfortunately this leaves no where for the red wire from the Aldon electronic ignition to go. Would it be possible and safe to put another terminal on the positive side of the existing standard coil so that the three items (stop light switch, overdrive and electronic ignition) could all run off the same coil? If this is not possible how would I go about rewiring the overdrive please? Not sure if this is important, but the car has been converted to an alternator. Many thanks Steve

Sounds like you need one of these little dudes.

: )

Stop! The coil has nothing at all to do with stop lights or overdrives! I don't know what you're looking at but the coil is the cylindrical thing with a big HT (high tension) lead going to the centre contact on the distributor cap. See thew attached diagram from Rimmers web site (I hope I haven't infringed any copyright).

Hi, The green wire attached to the positive terminal on the coil appears to be from the overdrive, when I removed the wire and tried it whilst on the move, the overdrive failed to engage, but engaged with no problem when I re-attached the green wire. Prehaps the overdrive has been wired up incorrectly in the past. Thanks Steve

Sounds like your overdrive has been retro-fitted to the car, and they've simply found the most convenient switched +12v line on the coil. Nothing wrong in that. The +ve terminal on the coil (on a negative earth car) is at +12v when the ignition is on. (this is not the case with Spits and GT6s equiped with balast restistors).
The aldon requires a +12v feed to make the magic work, so they suggest connecting it to the +ve terminal on the coil.

hope this helps
Paul

Just about any overdrive fitted to a Herald will be retro-fitted. Does look like someone has mucked up the wiring. Have a look where the stop lamp supply should come from. (This may depend on whether you have a hydraulically operated switch, or one mounted above the brake pedal.
Although as others have said, you are getting a switched supply by "piggybacking" off the coil contacts, it would be better to keep the coil feed separate. If things are OK at the moment, the Aldon is unlikely to increase the current flow by any great amount, but the original coil wires would only have been designed to take the ignition current. It's better to return to that, especially as it will reduce the chance of a fault elsewhere causing ignition problems.

Hi, where is the best place to wire the overdrive up, this car is now negative earth. Thanks Steve

I've just found that hats don't come in any palatable flavours 'cos I'm just eating mine!
Looking up the Herald 1200 +ve earth diagrams, I see that the stop lamps WERE fed from the coil! The -ve earth 1200s and 13/60s were fed from terminal 2 of the ignition switch.
I was going to suggest that you wired up the overdrive as per Vitesse, and have just looked up the Vitesse wiring diagrams. While the 2 litre had a separate feed from the fuse box to the overdrive circuit, the Vitesse 6 connected a white wire from the column switch to the COIL, (!!) which then fed terminal W2 on the overdrive operating relay.
The Spitfire and GT6 used the same (?) relay in a different fashion, and in their case W1 on the relay went to connector 2 on the ignition switch and C2 went to connector 1 on the ignition switch.
That said, it would still be a good idea to reduce the load on the wire from the ignition switch to coil by running a separate wire from the ignition switch to the overdrive circuit as although the Vitesse 6 used the coil terminal, its stop lamps were fed from the fusebox. So no car left the factory feeding ignition, overdrive AND stop lamps from the same feed. (2 out of 3, but not all 3).

The advice that you need a relay to operate the overdrive depends on which overdrive you have. The Canley Classics website has a useful advice section that can help you to identify overdrive types. If I recall, if the solenoid is on the left of the box (passenger side) you have a J type and do NOT need a relay, but if on the driver's side, it is a D type and you DO need a relay or you can overload the wiring and switch contacts. If you have a Herald type 3 synchro box, it WILL be a D type. If a 4 synchro Spitfire Mk4 type (with reverse next to 1st), then probably a D type but COULD be a J type. If a single rail box, (reverse next to 3rd?) then it will be a J type fitted.

Hi, I have discovered that the white wire on the bottom of the coil on the positive terminal is something to do with starting, when I removed this white wire, the car failed to start. It has got nothing to do with the stop light switch as I originally thought. Thanks Steve

You should check the manual for the wiring of the stop lamp and restore it to original (probably a green lead from the fuse box, possibly via the feed to the heater and instrument stabiliser). The overdrive should always be wired from the Ignition switch by means of a relay (the solenoid can draw a few amps as it gets older, particularly if it isn't carefully adjusted). If no relay is fitted then you should fit one (wiring diagram in all the manuals), the overdrive can overload the ignition switch (whether connected direct to the switch or anywhere else on the ignition controlled circuit. Then connect the Aldon/Pertronics Ignitor module as per the instructions. None of our cars are exactly flush with fuses and relays as standard, so don't trust POs bodged wiring, sort it out with correct guage wire and relays as appropriate

Section : Ignition and Distributers

Problems Connecting An Aldon Electronic Ignition

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Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition

Problems Connecting An Aldon Electronic Ignition