tosh

Ok bear with me as my wiring expertise is minimal.

I’m fitting an aftermarket low fluid level float switch to the Aluminium expansion tank that I want to trigger a buzzer and led light which are activated via a time delay relay, the trouble I have is that the float switch will only activate in the closed circuit position which is @ tank level full position, is there a way to make the buzzer/led light come on when in the “open circuit / broken circuit” position which will be when the float switch arm is in the down position (tank empty)

I know there’s probably a really easy way but unfortunately my brain can’t work it out!

This is how I’ve done it but probably totally wrong.

burnzy

That looks good to me, it’ll certainly do what your asking of it.

stwibs

if that's incorrect swap 87 to 87a
or turn the float switch 180 😂

burnzy

tosh

so it’s as simple as swapping the buzzer & LED + feed from 87 to 87a? I thought 87a was a permanent live?

yes it would work by rotating the float switch 180° but I would have to drill a hole near the bottom of the tank & get the existing hole tigged up or fill the expansion tank to the brim 😁

t230

i probably know the least but can polarity be reversed so it buzzes when low not high -

tosh

No I know the least and it’s me that’s wired th wrong way

The float switch has no polarity, they are a reed switch so either open or closed.

I THINK!!

burnzy

87a is a normally closed contact, 87 is normally open as per the schematic above.

in the diagram I’ve posted

t30 is your permanent supply for the timer and your switched output.

t15 is your signal wire, so your float switch

t31 is your relay ground

t87 is normally (open (off)

t87a is normally (closed (on)

so what you’ve done is right, you’ve fused your supply wire and put it onto t30

you’ve then split this feed to your float switch once the float switch is activated it sends +12v back to t15 which energises the timer once the timer times out it energises the contactor to switch across the +12v feed to t87

t87 has your LED and buzzer so they are now activated.

once topped up it’ll open the float contacts, stopping the +12v to t15 turning the light off

god I’m bored 🤣

edit: sorry my bad, it delays on operate. I’ve edited my reply as such

burnzy

I was just about to say it ideally wanted to be on delay not off delay to save nuisance tripping but yours is a 15 relay not 13 as per my diagram 🥴🤣 and as you have correctly identified in you first post 🤦🏻‍♂️🤣

tosh

Thanks burnzy for your in-depth help & description and patience with my stupidity “much appreciated mate”.

So would I be better of with a delay off Relay then? Would that work with my float switch orientation?

I'm probably really starting to sound thick now aren’t I

burnzy

No, its fine honestly mate.

what is your purpose of the delayed relay?

in my opinion your using the correct relay.

if the expansion tank isn’t baffled and your doing some hard cornering on track for instance, it may trigger the coolant switch when the water is forced to one side, so the time delay will stop it alerting you of a false alarm and triggering the light and buzzer straight away.

although I’d not have the time delay too long, I’m sure around the 15 seconds mark is more than enough to take into account a very long corner, but short enough that if you had a hose go and let all the coolant out it’d give you a chance before it was too late.

it can always be fine tuned on the relay if you do get any false alarms with that duration.

On another note your set up may not necessarily need a delay, you could make it just a couple of seconds because the float hight is enough that cornering doesn’t cause any issues, and the the tank is small enough that the water level doesn’t shift much.

food for thought anyway 👍

tosh

Yes exactly that to stop the annoying false alarm when exhilarating and cornering so 15 seconds delay is ample time.

I mocked it up to a 12v supply on the table last night and the float switch triggers in the wrong position So I think my only option is to just get the hole welded up and move it towards the tank!?

heres what I mean in a diagram because I’m crap at trying to explain in words what I mean


But will work with the float switch near the bottom of the tank as the circuit will be closed (ON) at low coolant level




It won’t work in my existing position as the float switch is in open circuit (OFF) at low coolant level

tosh

In reality This is all my brain sees when people try and explain car electrics to me

burnzy

If you used a “delay off” relay and swapped the buzzer and LED to terminal 87a it will work fine 👍

when the float switch is triggered and stops the +12v to the relay it will count down the 15 seconds and then switch the relay to the off position and then activate the buzzer and LED.

tosh

Cheers burnzy for your help mate there’s not many these days who could be bothered to take the time and effort to help someone out, especially if they are like me who make hard work of things that are probably so simple!

At least I can draw a good diagram though

burnzy

I forgot to mention that in my last post, your diagrams are spot on to be fair 👍🤣

where as mine are like computerised fag packet drawings 🤣

it’s fine honestly though mate, I do like to help when possible 👍

tosh

Cheers again burnzy for your help mate “It’s easy when you’ve got the correct parts for the job & know what you are doing

It’s now working as it should with the different relay, but knowing me I’ll probably never get round to putting it on the motor

I should of done more research when I ordered the bits but that was over a year ago, when I looked it up back then all the information I could find online was a diagram saying all you need is a time delay relay & float switch! Little did I know that the position and orientation of the float switch within the tank would make a difference or even know that timer delay relays come in both timer ON & timer OFF operation.

“ LIVE AND LEARN ”

burnzy

Well I’ll let you into a little secret, I’ve been waiting for a bit of kit to turn up from China for what has felt like a lifetime because of this Wuhan flu going around.

turned up 3 days ago, spent the rest of the day loading the software up then got the cluster from my lockup for my retro fit.

i was so excited the next day to fit it, I stripped the dash apart and it turns out I’ve bought the same style cluster I’ve already got 🤣🤦🏻‍♂️ It’s mono chrome and I wanted a colour FIS display 😩🤣 although I only gave £17 for the cluster so it became cannon fodder if I borked it learning to use the new software.

although it did go fine and I got round the component protection and mileage correction and now I’ve managed to figure out what the colour FIS clusters look like I’ve ordered hopefully the right one 🤣🤣


but in all seriousness, I’m glad it’s worked out good in the end 👍 plus it’s a bit more string in your bow 👍

tosh

Your not alone Everything I purchase expensive or cheap Always arrives either damaged - parts missing or the wrong item! bad luck in that case seems to follow me around, and mostly to no fault of my own “Honesty” But I do have a habit of not reading things properly before I buy them.

I don’t know about you but I ordered some roloc adapters which came from China and found myself disinfecting the plastic packaging with the Misses Detox worktop spray because of the Corona Virus

One thing I wish I knew more about is electronics but haven’t done enough of it to learn anything, basic House wiring is easy but automotive etc seems to be a minefield. Believe it or not my late uncle was high up in BA & was a Chief Engineer of Concord, long before it had the troubles I hasten to add, I wish I had his knowledge of electronic his loft was full of testing equipment that wouldn’t look out of place in the space station.

burnzy

🤣🤣 I had it delivered to my moms Address so I didn’t miss it, and I kid you not I told them my concerns and said to be careful, I sprayed it in the kitchen and they took the micky so badly I gave up and thought if we catch the Wuhan then it was probably easier to deal with than the ribbing I was getting, plus the box was full of electrical leads and plugs and it would of been a nightmare to disinfect 🤣🤣 I did wipe the cardboard box and the plastic carry case but gave up after that 🤣

I’m an electrician by trade but cars are a HUGE hobby to me, so my trade background helps me understand car electrics.

tosh

I’m glad I’m not alone with my thinking then I’ve got a few more things coming from Wish which also comes from our Chinese friends so thinking I might get my rubber gloves - respirator & polythene Onesie ready for when the postman comes

😷🦠