Header tank buzzer

[Stag therapy]

Post script. Armed with 12 volts of batteries, masking tape, some lengths of wire, a bulb, a cork and my youngest as a second pair of hands, the header tank and my logic was this evening tested in the kitchen. The bulb glowed very dimly until the water level reached quite a low stage and then immediately switched to full brightness. So the tank works. Just now need to find a suitable warning device. Just love acquiring new knowledge like this.

Many thanks to those who replied; particulalry Roger.

[Jeff]

No, why?

Mine seems to work in the opposite way.

[Pete]

Yep logic dictates float down makes connection up breaks connection. I was going to fit a buzzer to mine then I decided a drop in the header tank level was not a life or death situation so I fitted a warning light instead. I had visions of being out somewhere and the buzzer kept going off all the way home which would drive nuts but putting up with a flickering light is doable for me.

It is possible to get flashing LEDs, a sort of half way stage between a buzzer and a static light. If I was a Stag paranoic (?) I'd opt for that.

[LAMBRETTLAD]

What a great ,informative and interesting thread,with some fantastically knowledgeable members

[Pete]

Post script. Armed with 12 volts of batteries, masking tape, some lengths of wire, a bulb, a cork and my youngest as a second pair of hands, the header tank and my logic was this evening tested in the kitchen. The bulb glowed very dimly until the water level reached quite a low stage and then immediately switched to full brightness. So the tank works. Just now need to find a suitable warning device. Just love acquiring new knowledge like this.

Many thanks to those who replied; particulalry Roger.

There are two aspects to this - voltage and current. The dimness of the bulb could be down to both, not enough volts, current or both. So you could have twelve volts but if there was not enough current, then the bulb will be dim and vice versa so to speak. AN LED will either work or not - it requires two things to trigger it, a voltage threshold and sufficient current, which is why it is so difficult to dim the buggers and the simple rheostat that the Stag has is useless for panel LEDs. So - under these circumstances it may not be too difficult to work out a way of linking an LED to your tank. Set your multimeter up and measure the voltage where you bulb goes from dim to bright and we have something to work on. Also without batteries buzzers and bulbs attached try to get the resistance at that point too - you should see a marked change at the point where the bulb would kick in.

[Stag therapy]

Pete

I may have to come to back to you about this.
As I said in the linked thread, wiring the thing in is way down on my "to do" list. My priority at the moment is trying to rebuild a car that runs, fit it out and get it through its MOT by early April. A buzzer or light is a luxury, I'll live without for the time being.

Barry

[Blue Stripe]

Barry
I fitted a Merc tank (W202) last year. Firstly I linked into a warning light which worked fine. I then wanted to "up grade" to a warning buzzer. I replaced the light with a 12v warning buzzer. The issue was the buzzer was constantly on! I then re installed the light in parallel with the buzzer. The bulb had just enough resistance to keep the buzzer silent until the float switch fell and allowed more current to pass and the light and buzzer to send a warning!
Ian

[Stag therapy]

Ian

Many thanks. I shall bear that in mind.

Barry

[StagJonno]

Mine seems to work in the opposite way.

Possibly the float switch has been inverted, or from a different Merc??