Interesting relay problem...experts?

[nutt7]

So I recently added 2 relays to supply my ignition switched components to my fusebox. (if curious why, go here: http://coloradok5.com/forums/showthread.php?t=310188) One supplies the pink wires, the other the orange wire that supplies the PW, A/C. The one to the orange wire is a supplement, meaning that the original wire stayed connected at the fuse box, but I tapped it to trigger the relay, and then new power is fed to the same fuse buss. The relay supplying the the pink wire is not a supplement. It solely supplies the power there.

The problem: the "orange" relay remains engaged after the key is off. I can run my fan and windows with the key off. If I disconnect the trigger wire, it shuts down the relay and won't re-engage when I plug it back in (there is not 12v at the trigger wire).

I swapped relays, same thing. Check this out though...if I switch the two relays' trigger wires, both will operate just fine (how I have it now). It only remains engaged when the trigger wire is on 85 and the 87 wire runs to the buss where the trigger wire is tapped (and the original wire remains).

I think this "loop" must have something to do with it, but how?

Here is a pic of the buss. The brown runs to 85, the red is from 87, and obviously the orange is the original.

 

[Mastiff]

A little circuit diagram might help us understand how you have stuff rigged up.

 

[nutt7]

Here you go. Like I said, if I swap the brown wire at 86 with the pink on at 85 all works.

 

[rampage]

85 should be ground. On the left one you have ground going to 86. Is that just an error in your schematic?

 

[nutt7]

Yeah, I do have both 85s to signal and both 86s to ground, but the polarity of the coil doesn't matter, at least with these relays.

 

[Mastiff]

If I understand what you have going, you basically have the output of the second relay also providing the +12 to engage it, so it feeds itself. I think it makes sense that it would not be able to disengage. One option is to use the existing keyed +12 just to engage the relay, and let the relay feed all the circuits.

 

[DEMON44]

I can't see the schematic on my phone but that sounds like you have it wired up as a latching relay.

 

[Fordum]

Yep, its wired as a latching relay. Its easy to see why if you follow the power. You have +12 coming into 30. To turn on the relay, you put +12 to 86. When you do, the relay hooks the +12 from 30 to 87.
Since 87 is hooked to 86 through the fuse bus, the relay is continuously powered by its self once its turned on.

 

[nutt7]

Ah, Makes sense now. I was too focused on the 87 and 86 losing power with the key off, and didn't realize the supply was now eternally energizing the coil. At least now I know how to wire a latching relay. I should have figured that out! Thanks for the help!

 

[454Sub]

I did the same exact thing and tore my entire fusebox apart looking for a short before I realized it was my headlight relays.