18 replies to this topic

[dezshearer]

Hi guys, would it be safe to wire in a buzzer along with a warning light?

The sender switch wouldn't be overloaded or anything like that? It's a earth really isn't it?

[tiger99]

A small modern electronic buzzer will not require much current, so the switch will be just fine. A big old-fashioned electromechanical buzzer may be too much for it, and need a relay, but I doubt that you would want to fit one of these anyway.

[dezshearer]

http://www.ebay.co.u...1#ht_1626wt_989

Something like that!

Thanks, i'll give it a shot!

Edited by dezshearer, 11 September 2012 - 08:29 PM.

[tiger99]

Yes, that should be ideal.

[xrocketengineer]

I might be wrong but if you connect the buzzer to a 12VDC feed you might need to connect a diode in series with the warning light wire. The reason being is that the light power comes from the voltage stabiliser and for the buzzer from 12VDC. While the pressure switch is open there could be some voltage fed back from the buzzer to the warning light affecting all the instruments fed by the voltage stabiliser.

[dezshearer]

As far as I can tell, the oil pressure warning light(brown/white) and battery charge/ignition(brown/yellow) light both run direct from the ignition live (white).

The voltage stabilizer is only used for the water temp(blue/green? It is on mine anyway...) and petrol gauge (green/black).

The oil pressure and charge lights are both "earths".. can't see why they'd need to be stabilized?

I'm only worried about shorting the oil pressure switch, and making it fuse closed!

edit: spelling.

Edited by dezshearer, 11 September 2012 - 11:26 PM.

[xrocketengineer]

You are correct, my eyes are screwed up. The oil pressure warning light is connected to the white ignition wire. So, it should work like tiger said. It should only need a few milliamps.

[dezshearer]

Well I'll let you guys know!

[1984mini25]

The biggest problem is buy the time the oil light does come on, the oil pressure has already dropped to the point of doing damage. The light comes on around 8psi, but you need at least 20psi at tick over when warm...

[bmcecosse]

Exactly - ^^^^^ - it's a waste of time and energy........ Fit an oil pressure gauge and keep an eye on it!

[mike.]

But can't you get a switch which comes on at about 15-20psi?

[The Principal]

Minispares will sell you a 20PSI Oil Pressure switch for £7 - http://www.minispare...|Back to search

[dezshearer]

Out of stock unfortunately.


I have an oil pressure gauge, I watch it a good bit, but for those times when I'm worrying about the road, and looking out the window, I might not catch the glow of a bulb, but I'll definitely hear a buzzer.

[dezshearer]

I wired the buzzer up in parallel to the light, and it worked, briefly.

Now the light won't go out and the buzzer stays on, but my oil pressure is fine according to the gauge, it's sitting at 70.

I think I shorted my pressure switch, due to fumbling about with the connectors (blue spark, so no doubt welded the switch shut at the other end).

I've ordered a new one to replace it. Poor little guy never stood a chance!

[Pete649]

The biggest problem is buy the time the oil light does come on, the oil pressure has already dropped to the point of doing damage. The light comes on around 8psi, but you need at least 20psi at tick over when warm...

That's true, but I had a Lotus Sunbeam track car and it used to suffer from oil surging on hard acceleration if the oil level was not topped up to a certain level (even with a baffled sump). I fitted a buzzer which drew my attention to the split second low oil pressure without me having to watch the oil gauge all the time. Worked a treat.