White dot on terminals. Is this the positive or negative...?

[aditya]

FWIW, if the driver's on a horn I use 9V to 'pop' it and with a piece of TP 'flapper' taped to dangle over the horn mouth, whichever terminal moves it out with the [+] lead is positive. Otherwise, a 1.5 V with a 'flapper' taped over the driver 'mouth'.

GM

Brilliant idea for testing the polarity of a hf-driver while still on the horn. Thanks for sharing it with.