View Full Version : What causes relays to buzz

11-19-2007, 12:16 PM
Ok like the title states. I have two Hella relays that seem to work fine, when hooked to the rear locker. When hooking up the front locker to these same relays they buzz. The ground is fine, I did read that if there is a low amount of voltage coming into the relays they can buzz.

I Googled just about every possibility with no luck..........HELP!!!

11-19-2007, 12:19 PM
Yeah, that will do it. The voltage is enough to cause the relay to start to pick, but the current draw causes a voltage drop which then drops below the 'pick' threshold.

Another source is miswiring - could the relay be opening its own voltage source once it picks? In other words, is Vcc to the hot side of the coil actually going through the normally closed relay contact, so that when the relay picks it opens its own coil circuit?

Uncle Ben
11-19-2007, 12:27 PM
Relays buzz because of voltage inconsistencies. Make sure your ground is real and not just to a painted body part and make sure voltage is sufficient in the exciter circuit. If the contacts are burnt it could also cause some chattering.

11-19-2007, 01:27 PM
Both front and rear are wired the same as in the power comes from the fuse box and splits to the relays. Same goes for the ground, both are grounded to the same bolt. I sanded the area again and checked the rear. Rear works fine with both motors and the same power supply as the front and ground. I checked the motor ground wire that is grounded to the frame and it is fine too.

I basically gave up while typing this and bought a wiring harness from ORS, they started all this wiring mess GGGRRRRR. Anyway I just ordered it and should be done on Wednesday for me to pick up. Then I still need to install it sometime before Friday, that should be fun............

Thanks for the help guys I really appreciate it. I am just done with the front wiring mess and am ready to have my front locker work every time I push the button.

Thanks again.

PS Kevin did you decide on the monitors? LMK one way or another, if no I will list them FS here first.

11-19-2007, 01:39 PM
Perhaps one of the limit switches is wired in series with the relay coil, by design? Not the best setup, but lots of guys do that. A dirty limit switch could cause the relay to buzz. If that is the case a new harness won't change anything.

11-19-2007, 06:26 PM
The new harness is one from ORS, nothing needed than pluging it in and hooking it up to the locker. $130 for the whole unit, take a look. http://www.tacomaterritory.com/forum/showthread.php?p=1022802

11-20-2007, 08:01 AM
Yeah, familiar with it - and considering getting one for my Taco upgrade - but they still use the limit switches in the locker itself. Worth 'ringing out' with a meter.