1964 S type

[Norton]

Thank you all.
Switch on my car looks like a newer replacement. Found green wire broken at connector, maybe done that myself as I was working on distributor ( checking points gap and timing ignition ). Been driving without brakelights for a while.

I mentioned two green wires with black tracer ( cut off on my car ) harnessed together with green wire connected to this switch. Anyone any idea what theese should be connected to? Only green/black wires I find on eldia is windshield washer, voltage stabilizer.

Harald

[cass3958]

Harald can you post a picture of th etop of your engine taken from the right side looking over the carbs. Green is normally power and Green Black can be a continuation of the green wire once it has passed the object that has been powered. For instance there is a green wire that goes to the starter solenoid then a green black wire coming from the solenoid to the Otter switch on top of the inlet manifold. We have discussed the Otter switch many times on the forum and often owners have rewired the Solenoid so they have a switch inside the cabin which by passes the Otter switch.
With the photo as requested we might be able to see what is missing or been added.

[Norton]

Hello.
Here is a picture. Have done some checking. Brake switch, the red wire powers the stop light, replacement for original at some point for some reason. Green energized with ignition.
Where the green wire emerges from the harness, there are two green black wires whitch are cut off. Red circkles on pickture. They are not energized with ignition on. Originally to stop ligths, aed?

Have read quit a few posts regarding otter switch / aed. PO have fitted a switch below dash to power aed, with a «on» warning light. I have been fiddling with that switch trying to figure out what it is doing. And I was sure the aed was off with hot engine whether or not the switch was on. Turning switch on/off with cold engine a distinguished difference. Engine need aed/«choke» when cold. «Hissing» sound with switch on.
Turning switch on/off with hot engine - no difference and no hissing sound. So I assumed otter-switch was in operation. However when doing some cheks with engine not running ( cold ): Aed solenoid clicks with switch on / off. Also with jump wire directly from battery. But also operates when I disconnected green black wire ( see pickture ) from otter switch. Understand if otter switch is wired into the circuit, aed should not operate with this wire disconnected? I will check more next time engine is hot.

Rgds Harald.

[NigelW]

With regard to minimising power through the brake switch, LED bulbs can be fitted. I haven't had to replace a switch since I did this.

[cass3958]

I will have a look under my bonnet tomorrow but looking at the wiring diagram the only Green/Black wire I can find is for the AED solenoid. My thinking is that if you have a switch on the dash the wiring to the AED might have been altered and the two original wires disconnected.

Down that side of the car there should be wires for the horns, right front lights, AED, coil, Brake warning to the reservoir, Wiper motor. Brake light switch, Oil pressure warning and water temp. I think that is all. The only one of these that is Green/Black is for the AED.

I will investigate tomorrow for you and add some photos of how my wiring runs.

[John Quilter]

Not heard of any oil pressure warning lamp. Was that a later fitment and if so where was the warning lamp located? All the cars I've seen just have the gauge.

[cass3958]

No warning light John I was just referring to the Oil pressure switch as a warning device but it is connected to the gauge not a bulb.

I have had a look down the side of my engine today and as I thought I can only see one Green Black wire that comes from the wiring loom where your cut wires are and this goes to the AED. My thoughts remain that someone had rewired your AED to fit the switch on the dash but have not used the original wiring.

[John Quilter]

From earlier post:


"Turning switch on/off with hot engine - no difference and no hissing sound. So I assumed otter-switch was in operation".

I find with my car that turning the manual switch for the AED on with the engine running will usually not cause the AED to operate as evidenced by no hissing. Blipping the throttle will cause it to come on. I suspect higher engine vacuum prevents it from kicking in. I think the AED was intended to come on from a cold start with the engine off.

[Norton]

Thanks for information and inspiration.
Have now had time to investigate. AED on my car is, as I mentioned powered by a switch and it is permanently grounded. Green/ black wire from otter switch is one of the wires cut off. The other green/ black I still don’t know, maybe original stop ligths. So whenever switch is on, AED is in operation ( it «opens»). Have also read the service manual and think I understand how it works. It have two modes, one at «idle and light cruising condition» and secondly at «open throttle or full power operation». Idle; the low pressure ( high vaccum ) in manifold «sucks» the needle ( the one that pokes out at the top, with adjuster nut ) down against a light spring, and at open throttle with higher pressure in manifold the spring pushes neddle upwards and opens for richer mixture. As I understand from service manual the hissing sound is only when needle is at lowest position, idle and light cruising cond. Originally, green wire to AED is enegized whenever ignition is on, and is controlled on / off with otter switch. Witch should be closed whenever temperarure is below about 30 - 35 ˚C. When it opens, AED closes.

My otter switch is closed when engine is cold, but I think it opens too early. Probably the reason it is omitted and a switch to power AED is installed. I was checking continuity of otter switch as engine warmed up, and when it opened, engine was not warm enough to run on normal carburation.
Planning on replacing otter switch but keep the on/off switch below dash. It is wired from a connection at a fuse (30A) holder. Probably vise to wire in a 2 or 3A fuse. Coil in AED draws about 150mA. A lot of things can happen before the 30A fuse blows. And if the AED coil fails or a shortage in wiring occurs, the small fuse will blow and save the larger one and items connected to the 30A fuse will not be affected. ( Hopefully )
Rgds Harald

[John Quilter]

"My otter switch is closed when engine is cold, but I think it opens too early. Probably the reason it is omitted and a switch to power AED is installed. I was checking continuity of otter switch as engine warmed up, and when it opened, engine was not warm enough to run on normal carburation.
Planning on replacing otter switch but keep the on/off switch below dash."

That is exactly what I did on my car and fitted a warning lamp to remind me to turn it off.