My Main Relay Won't Stop Clicking... Wtf?

[LD50]

I am wiring up a tach, and I stopped, reconnected my battery, and all of a sudden theres a continuous clicking noise... I find that its coming from my main relay on the pass side in the engine bay in the small rectangular relay box.

 

What's going on and how do I make it stop????? The only thing I have changed is that I have main power and ground wired to my tach from the ignition source, same place as my deck.

Edited April 18, 2007 by LD50

[mws]

How's the battery and the connections?

 

A machine gun clicking relay means it is getting enough voltage to trip, then not enough, then enough, then not enough. If the battery is weak, it may be right on the edge. Has just enough to trip it, but then with things start turning on and pulling current, the voltage drops just enough to not be able to keep the relay coil energized so it opens back up. Once the draw is gone, battery voltage comes back up, relay coil energizes and the cycle repeats.

 

If you are getting clean and steady 12 volts to the relay coil, then the relay needs to be replaced.

[LD50]

How's the battery and the connections?

 

A machine gun clicking relay means it is getting enough voltage to trip, then not enough, then enough, then not enough. If the battery is weak, it may be right on the edge. Has just enough to trip it, but then with things start turning on and pulling current, the voltage drops just enough to not be able to keep the relay coil energized so it opens back up. Once the draw is gone, battery voltage comes back up, relay coil energizes and the cycle repeats.

 

If you are getting clean and steady 12 volts to the relay coil, then the relay needs to be replaced.

 

Thanks for the explanation, that tells me how I need to go about fixing this. My next question is, can I drive with this problem? I started the pathfinder and I dont hear the clicking, pnly when the pathfinder is off. Is a constantly working relay like that a fire hazard?

[mws]

Are you saying it is clicking when the key is off?

Or clicking when the key is on run but engine is off?

 

I am not seeing how it would be a safety issue, but it is pretty hard on the relay. They are usually designed for about 10,000 cycles. So you're using up a bit of life on the poor guy!

 

More importantly, if it is a voltage supply issue, you are probably getting awfully close to some other less tolerable symptoms (like no runny). Check out the battery and charging systems. If they are OK, start checking all the connections. A dirty/loose connection can drop the voltage significantly without being an open.

 

BTW, I got the package this week and hope to send a return to you next week. Can you PM your address to me? I can't quite make out the address on the package.

[LD50]

It was clicking with power off, no key.. nothing. I removed the ground and power wires I had used for the tach, and everything is now back to normal. Easy fix, but now I need to get a different power source for the tach I guess, oh well.

Edited April 19, 2007 by LD50

[mws]

OK, now that was a problem with your wiring! Somehow you were feeding an constant electrical signal back where it didn't belong. Double check instructions and then re-try different connections. What you thought was something wasn't. If that makes sense....