I'm planning on wiring some extra lights on my xj. While searching through wiring diagrams for the relays, I noticed some show 85 as being the ground and 86 going to the switch. others show these just opposite (85-switch & 86-ground). which is correct or doesn't it matter?

 

You can switch either the ground side or the positive side. As long as you are breaking the circuit. I like disrupting the power side but either will work fine.

Max

 

It does not matter, I have seen them with 12V on the 85 pin and on the 86.

What you need to know is

85 and 86 pins are the coil, you need ground in one of them and positive in the other one, this is where you run a switch, and again the switch can be on the ground or on the positive (also have seen both configurations)

30 pin is the source of power, it should come from the battery (fuse line) or from a known good capacity contact (I have used a line from the battery in ocassions, and depending on the vehicle I have used also a line from the fuse box)

87 pin is the NO (Normal Open) contact of the relay, it will not have power with the circuit open on the previous explained pins 85 and 86, and will activate one the circuit is closed on those two

87a pin is the NC (Normal Closed) exactly the opposite as the previous pin, it will remain powered when the coil pins are not activated, and will de-power when the circuit is closed.


a great number of things can be done with relays, in this case you can find a relay with two pins numbered 87 (just 87), in that way you can run a line from each 87 contact to each light.

hope this helps a little

 

thanks for the info! One less thing to worry about.