Warning siren

[omega2]

Help required, our set up Ignition/charging system consists of Lucas ACR alternator B+ to battery and Ind through ammeter to ignition switch, we have low oil and excess heat manifold warnings on instrument panel and sirens. However as most on here will know when they have activated the engine is at the point of seizure, at least with Sabres they are, I would like to get an audible warning as soon as the alternator belt gets thrown, I know we can monitor the rev counter and ammeter but there are a lot more things to watch out for, any advise warmly welcomed.

 

[omega2]

help required, our set up ignition/charging system consists of lucas acr alternator b+ to battery and ind through ammeter to ignition switch, we have low oil and excess heat manifold warnings on instrument panel and sirens. However as most on here will know when they have activated the engine is at the point of seizure, at least with sabres they are, i would like to get an audible warning as soon as the alternator belt gets thrown, i know we can monitor the rev counter and ammeter but there are a lot more things to watch out for, any advise warmly welcomed.

201 looks and no answer????

 

[Forty_Two]

201 looks and no answer????

Here you go, I have exactly this. I have diode split charging so have a relay connected via a small fuse to the Alt output. Because of the diodes the relay doesn't see the battery volts only the Alt output. Other side of relay to 0v. Alt good relay operates warning light turned off, bad relay releases light & alarm on.

If you don't use split diode charging you could connect the relay between the Alt out (with fuse) & +12v (also fused). When Alt good relay released as only a volt or two difference, Alt no output relay operates as will see 0v though the Alt diodes.

 

[omega2]

Thank you 42, will set up as you suggest.