Coil immobilisation

Post by **candy** » Sat Sep 27, 2008 1:05 pm

Hi, When shorting the coil to earth , i take it that it should be done on the switch side of the coil . Correct me if i,m wrong. I found a switch by the wiper motor ,under the dash and there was an extra wire on one of the posts but i have forgotten which side. Just changed the loom so chopped all old wire out. Also there was a 'Selmar' (70's ?) car alarm on the bulkhead with a couple of wires that ended up in the boot attached to a keyed barrel. 56 4 door splitty.

Post by **rayofleamington** » Sat Sep 27, 2008 1:14 pm

The points take the coil circuit to ground (when closed).
Therefore if you take an extra wire from the points side of the coil to a switch to ground you are replicating what the points do and this will stop the points from having an effect when the engine is turned (i.e. no spark). You can also patch in to the circuit at the points connector.

If the wire and switch are less obvious then they offer more protection.

Post by **bmcecosse** » Sat Sep 27, 2008 6:57 pm

But when you do that - you are dragging current through the coil to ground all the time (if ignition switched on - and the hidden switch is closed) - so the coil will overheat and the battery run flat! I prefer to simply interrupt the feed to the coil - same effect, engine won't go - and no current drain or overheating coil. But on Minor with electric pump - the hidden pump switch is king!

linearaudio · Post by **linearaudio** » Sat Sep 27, 2008 7:49 pm

For convenience, I used the little known (edited on the grounds of security, Kevin) as a ********* who wants to •••••••••• (edited on the grounds of security, Andrew

) ?

Post by **bmcecosse** » Sat Sep 27, 2008 8:49 pm

It 'may' not have enough current carrying capacity! But - you shouldn't reveal your little secrets like that on a public forum anyway!

linearaudio · Post by **linearaudio** » Sat Sep 27, 2008 9:22 pm

Post by **candy** » Sun Sep 28, 2008 7:05 am

Ta, I,ll tap into the supply to the coil and do another likewise with the fuel pump.

Post by **Alec** » Sun Sep 28, 2008 7:45 am

Hello Candy,

as the ignition switch feeds both the coil and the fuel pump, then one switch directly after the ignition switch will do both together.

Alec

Post by **bmcecosse** » Sun Sep 28, 2008 11:08 am

The beauty of the pump switch is - the car starts and they may begin to drive away, and then to their dismay it cuts out! They have now moved the car and are looking pretty obvious - so they are likely to abandon it and run away. A coil (or general ignition) cut out switch means the car won't start - they may then quietly find a way to 'hotwire' it - it's very very easy, and I won't tell how on here! - and off they go with your car.

Post by **rayofleamington** » Sun Sep 28, 2008 5:21 pm

you are dragging current through the coil to ground all the time (if ignition switched on -

You are doing exactly that if the points are closed, so with or without a switched ground for security you can heat the coil and drain the battery.

Post by **bmcecosse** » Sun Sep 28, 2008 6:41 pm

Indeed - which is why the car should never be left for any time with the ignition ON and the engine not running!

Post by **Rob_Jennings** » Mon Sep 29, 2008 4:43 pm

but at the end of the day if it did burn out the coil and flatten the battery that is nothing compared to the loss of the car.

Its a neat solution in that if done correctly it is virtually invisable and would required a bit of messy engine dagnostics to find, also it has a fail safe aspect in that if the mod fails it tends to leave things as they were so it all still works, adding a switch on the live side of the coil adds another potential point of failure to the system.

pump stop switches are very obvious to anyone who knows a minor well (we all expect the pump tick when we turn the key)