57 replies to this topic

[stuart bowes]

additional question (sorry again)

 

with this set up, if the oil pressure lights up during driving (i.e. actual oil pressure issue) would the brake warning also trigger

 

not a major issue of course, would want to pull over anyway. but worth knowing

Edited by stuart bowes, 05 May 2023 - 12:48 PM.

[PoolGuy]

It was discussed a while ago, it seems that no one actually knows if it's required? Those who think it's an MOT requirement, when did it become such? I had a quick look and couldn't find anything in the MOT test that specifically mentions it separately from general warning lights, (if it's fitted it must work, blah blah).

[Icey]

additional question (sorry again)

 

with this set up, if the oil pressure lights up during driving (i.e. actual oil pressure issue) would the brake warning also trigger

 

not a major issue of course, would want to pull over anyway. but worth knowing

I'm curious, why do you think it would? Short answer is no, it won't, different circuit.

For the MOT question, my anecdote is that I don't have that switch (I don't have any of the original dash switches), just a normal warning lamp and it's never been mentioned during an MOT.

[stuart bowes]

that question was related to the modification noted in posts 12 / 14 / 15 which puts them onto the same circuit

 

the gist is that the lamp comes on with the oil warning light at start up which performs the lamp test.  and then if i understand correctly also means the lamp will also come on in actual brake fluid low conditions

 

but if my understanding of the diagram is correct it would also mean that it lights up with the oil low warning as well .. unless i'm failing to grasp the point of the diode which is entirely possible of course

[stuart bowes]

(if it's fitted it must work).

 

exactly.. in which case, just dont fit it :)  sorted 

 

maybe it depends how well the MOT man knows minis.  unfortunately my one is a bit of a classic car buff (or, fortunately, depending how you look at it, he's certainly very interesting to chat to)

Edited by stuart bowes, 05 May 2023 - 02:50 PM.

[PoolGuy]

 

(if it's fitted it must work).

 

exactly.. in which case, just dont fit it :)  sorted 

 

maybe it depends how well the MOT man knows minis.  unfortunately my one is a bit of a classic car buff (or, fortunately, depending how you look at it, he's certainly very interesting to chat to)

 

That's why I asked for some info from those who says it's required for the MOT, what model year would this be from?

[mbolt998]

It was discussed a while ago, it seems that no one actually knows if it's required? Those who think it's an MOT requirement, when did it become such? I had a quick look and couldn't find anything in the MOT test that specifically mentions it separately from general warning lights, (if it's fitted it must work, blah blah).

It probably is covered under "if it's fitted it must work". And new cars had to have this warning light, presumably after some year, because that's how the Mini ended up with that weird switch anyway (which is kind of a hack). So it probably is technically an MOT failure. But as I said upthread mine never worked and I never failed an MOT for this back in the 90s. But you have to bear in mind I only took it to the same two or three garages and they just might not have been clear on the rules. Minis were pretty common back then but it's still a quirky feature and a lot of people didn't really know what that button was for. Always amuses me that in a car that only has about 4 switches in it, one of them is this thing that no other car has!

[mbolt998]

that's a good point actually what is it, 5 more years and no MOT for this car anyway ? something like that

Yes I think it's 40y so you should be good from 2028. My car is 1979 :)

[Icey]

the gist is that the lamp comes on with the oil warning light at start up which performs the lamp test.  and then if i understand correctly also means the lamp will also come on in actual brake fluid low conditions

In a Mini there's no 'test', the oil lamp lights because there's no oil pressure, the 'battery/charge' lamp lights because the field coils are being powered from the battery - each is doing what they're supposed to, not being tested.

[KTS]

 

the gist is that the lamp comes on with the oil warning light at start up which performs the lamp test.  and then if i understand correctly also means the lamp will also come on in actual brake fluid low conditions

In a Mini there's no 'test', the oil lamp lights because there's no oil pressure, the 'battery/charge' lamp lights because the field coils are being powered from the battery - each is doing what they're supposed to, not being tested.

 

 

..he's referring to the setup that Spider mentioned on the previous page which uses a (diode protected) additional ground for the fluid level warning lamp via the oil pressure switch.

[stuart bowes]

The whole point of this thread is the test button which tests the working of the lamp for the brake warning light

So in that respect there definitely is a 'test' and the oil pressure light comes on before you start as well which is probably just because the pressure hasn't built up but it serves as a test of the lamp as well. That's what we're discussing piggy backing on to

Edited by stuart bowes, 05 May 2023 - 04:25 PM.

[KTS]

to be fair, the title of the thread is asking if the switch is necessary

 

the switch itself serves 2 purposes:

1. to alert you to a low fluid level in the master cylinder by way of a lamp built into the switch
2. to test the lamp bulb is working by pressing the switch

so what is it you're asking : do you need to be able to test the fluid level warning bulb is working, or do you need a fluid level warning indicator ?

[Lplus]

to be fair, the title of the thread is asking if the switch is necessary

 

the switch itself serves 2 purposes:

1. to alert you to a low fluid level in the master cylinder by way of a lamp built into the switch
2. to test the lamp bulb is working by pressing the switch

so what is it you're asking : do you need to be able to test the fluid level warning bulb is working, or do you need a fluid level warning indicator ?

Or alert you to one circuit failing by way of the sensor on the master cylinder body, depending on the age of the vehicle.

Edited by Lplus, 05 May 2023 - 04:51 PM.

[stuart bowes]

It started of as can I get rid of that switch (and therefore just rely on the sensor to illuminate the dash warning light when necessary)

But then it was pointed out that the lamp test is required

So now it's become basically how do I make that warning light illuminate on ignition pos1 and then go out again when engine running. I.e providing the required lamp test without needing the button

The solution has been provided now- by piggy backing the oil sensor. And I have a spare diode 12v rated 6a which I'm sure is more than sufficient..

The only question remaining is does that mean the oil failure whilst driving will illuminate the brake warning light as well.. really trying to focus down on that one question based on the small wiring diagram from page 1

[stuart bowes]

Which by the way even if it is an mot requirement (which I'm willing to accept) still is a bit moot because even though it tests the lamp it doesn't test the sensor

So really the best 'test' would be a) visually check your fluid or b) pull the lid off thus triggering the warning light which proves both sensor and warning lamp