Morris Minor Owners Club

Having fitted a fuel pump isolator switch, is there any easy way that I could wire up the "spare" light in the speedo to give me a warning when the fuel pump is turned off when the ignition is on? Just to help prevent the inevitable

You would need to use a lamp that was isolated from the speedo - like the Ign bulb holder, or one of the oil warning lights - and connect that across the switch. It will then glow when the switch is OFF, and the Ign ON. You could do the same with a buzzer - but that may attract the attention of the thief.....which rather defeats the object of the exercise.

or could you not do what i did with my switch and have it interrupt the low tension side of the ignition circuit to? then it wont go anywhere at all and you'll soon remember why!

bmcecosse wrote:You would need to use a lamp that was isolated from the speedo - like the Ign bulb holder, or one of the oil warning lights - and connect that across the switch. It will then glow when the switch is OFF, and the Ign ON. You could do the same with a buzzer - but that may attract the attention of the thief.....which rather defeats the object of the exercise.

Sorry Roy, Not quite sure what you mean by across the switch. Any chance of a diagram? I did mean to use the "blocked filter" light as its not got anything to connect to anyway at the mo

if you wanted a light, how bout having the light inline with a resistor, parellel to the switch, then when the switch is earthed the current is pulled down through the switch, and when the switch is off, so the fuel pump is off, it runs though the bulb, thus glows!

just do what i did, get half a mile down the road, and when it starts to splutter, spend 5 seconds thinking 'what could this be?' and wait for it to sink in! well that's what i did for the first month with the switch fitted, now it's second nature!

Is this the sort of thing you need? Sorry the right side of the picture went missing, it was only the battery.[frame][/frame]

sorry to be a pain chaps but i am planning on fitting a fuel isolator... I have the bonnet up every morning before i leave so forgetting shouldnt be a problem! but i was wondering how you did it? Whats the most effective way to install it, where does the switch go etc, and can a complete elctrical amateur do it! PM me with details if that would be possible, (dont want the bastards finding out now do we!) thanks you

Jamie

what i did was use an minor wiper switch. as it's just an on-off so it's perfect. found the live feed to the fuel pump (it passes accross the dash), cut it, crimped spades onto each exposed end and (using an ammeter to work out how the switch is wired - lots of terminals!) connected both ends to the switch. the switch is then on the dash where the screenwash plunger used to be (now got electric screenwash so switch is elsewhere) and it looks perfectly standard. a proper minor expert would probably notice that it's got too many switches, and work it out. but anybody else stealing it will just think they've broken down after getting half a mile!

you can fit the switch wherever you want, but that could entail extending the wires. then you could have the switch hidden under the dash so you have to grovel around and find it.

i'm not too worried about telling the world about my isolator... i haven't said where all the other ones are plus i have a steering wheel lock that goes under the handbrake, so you can't steer or roll the car anywhere! unless you take the steering wheel off!

another good tip, although it will get your hands muckier, and take longer, is to pop the bonnet and take out the rotor arm and put it in your pocket! or unplug something that you can remember where it goes. the unplugging trick isn't fool proof as the wire will be floating and it could be quite obvious to plug it back in. on the bright side, anything like that will slow a theif down, and maybe get them to give up and try another car.

My switch is hidden. essentially speaking what I did was pull that part of the wiring loom back into the car, strip the fuel pump live feed out of it, as far back as needed to reach the relevant switch. I then ran another wire (same colour) from the switch to the fuel pump and wound it all back into the loom so it looks pretty standard.

handy! will be looking into options over the comming week!

Don't do what I did on one of my cars and hide it in such an inaccessible location that you have to either lie flat out across the seats or get the passenger to operate it for you! ;)

Better to just hide the switch than make it a nuisance to operate, that way you wont be tempted not to use it because you will only be a minute.
And if you forget it you don't need to do any gymnastics to switch it on again.

" Across the switch " is just that - connect the two leads for the lamp to the switch - on on each side. Thus when the switch is OFF - current will flow through the lamp to earth through the pump. It should be enough to light the bulb - but not enough to click the pump...........

if you put a largish resistor before the lamp it would ensure that theres not enough power for the pump, and ensure that when the switch is on that the lamp is fully off with no residual glow.

When the switch is ON the lamp will be short circuited! There's no chance it will glow!! The lamp itself is a high resistance - nothing additional required.

ah ok, didnt reaise the lamps had high resistance, never mind then!

The lower the wattage = the higher the resistance, assuming same voltage........

yeah i dont know why that didnt occur to me =/

Something like this...



And there can, obviously be a common voltage source... as roy says you could literally wire the bulb across the switch