12v relay buzzing at 3v

Could any one help me with a problem I have please I have a 12v relay that has a dual voltage going to it basically when I turn my car lights on i have 3v volts going to my new relay and it buzzes because of not full voltage I would like to stop this and make it operate at around 10v-12v only could any one help please new boy UK here

Insert a diode or a few - eg common IN400x series (4001, 4004 etc). But probably any diode(s) will do - they merely have to handle the relay current. Each diode will drop about ~0.6V, hence 2 will drop ~1.2V etc. That should drop the relay voltage below its drop out voltage. Meanwhile losing .6 or 1.2V off the on voltage of ~12V should not make much difference. (Exceptions - a relay switching high current; diodes with 0.2-0.3 voltage drops like ancient Germanium & some Schottky. Strictly speaking, the voltage should be cleaned up thru a comparator or transistor or (maybe easiest) a FET, but suck it & see if it works...)

Thanks for the reply so i need to put a few diodes in series with the relay on the 0v- or the 12v+ also some one else said to try a zenor diode would that work ????

A little more info for you on my project I have upgrade my rear lights on car to leds my old side light doubled up as a fog when its was given the full 12v but only 3v volts when in side mode so ive fitted a relay in line with the supply to the fog light so when i turn the fog on the relay operates which works but when the side lights are on the relay buzzes hope this helps any one with my prob

Zener diode won't work with out either a cap or a resistor I believe but why are you getting 3volts in the system or do you have those POS LED lights. Howie ll THE only real auto electrics guy.

As above your post

Sorry JR, your post arrived before I completed mine, just proves how good I am at auto electrics! Install a second (LEGAL) rear fog and the problem will go away.

yes that would be easy but i would like my new fog light to work properly and stop the buzzing in my boot

forgot to say the new lights are from a newer model and are legal but work slightly different to my wiring

I'm with Howie. (Howie ll THE only real auto electrics guy.) A forward biased zenor is merely a diode. Reverse biased it doesn't conduct until above its breakdown voltage - eg, a 3.0V zenor would be equivalent to 5 x 0.6V diodes (but mounted opposite direction). Make sure the zenor voltage times its current does not exceed its power rating (Watts). +ve or -ve side should not matter.