Can someone please explain this wire diagram for me? It's from a 5pin Bosch 20/30 amp relay. Thanks

 

When the relay is off, 30 is connected to 86a. When you apply power between 85 and 86, 30 is connected to 87.

 

Hmmmm ok so 12v to both 85 and 86 will create power to 87? So hook up 87 to the source I want to power?
And where's the ground? 86a?

 

You pic died, but here's a shot.

Connect 85 to ground. When you apply power to 86, the relay will switch. Or you can give power to one side and switch the ground on the other side.

Next you need to think of whether you want power on until the relay clicks, or no power until the relay clicks. Give power to 30. If you want power until the relay switches it off, connect your device to 86a. If you want power off until you switch the relay, connect your device to 87.

There's tons of info here:

http://www.the12volt.com/

 

Way over on the right of your picture is an un-labeled empty box. Sometimes Bosch uses that kind of picture when the relay isn't a simple relay. Like maybe a timer or something else.

What drdisco69 says is right, but IF(?) that's a timer relay, maybe after you turn off power to 86/85, the relay stays on for a short time before turning off? Play around with a multi-meter & see what it does.

 

I took the unlabeled box to be a diode.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">I took the unlabeled box to be a diode.</TD></TR></TABLE>Maybe? If so, it'll just short if you reverse polarity 85 vs. 86. But depending on where that picture actually comes from, I know they use some funky symbols to represent 'relays' that actually have a variety of stuff inside. Including some solid-state timers that are way to complicated to actually draw the circuit.

 

True, because there's no polarity indicated for it to be a diode. Poopy picture all around, but functional I suppose.