buzzing 5 pin relay

[jemmos]

hey guys, my bro in law has two work lights on the back of his patrol running off the second battery. when switched on ( negitively switched) the relay ( 5 pin) buzzes and the lights dont work, but when the truck is started the buzz stops and they work?? they have been on the car for a year or so, only just started doing it? got me buggered. any help is much appreciated!! thanks

[Shadow]

hey guys, my bro in law has two work lights on the back of his patrol running off the second battery. when switched on ( negitively switched) the relay ( 5 pin) buzzes and the lights dont work, but when the truck is started the buzz stops and they work?? they have been on the car for a year or so, only just started doing it? got me buggered. any help is much appreciated!! thanks

could be a dodgy relay(water inside??), its taking 13+volts(alternator) to throw. The lower voltage from the battery cant do it maybe?

relays should switch at about 7volts. I would try a new relay first.

[jemmos]

thanks shadow, yeah tried another relay with the same result. ill test the volts at the relay and see how i go. thanks

[jemmos]

turns out you were right shadow, not enough volts from 2nd battery. 2nd battery is fizzed! thanks for your help mate