30 AMP Relay wiring?

[barillms]

Can somebody post a 30 AMP relay wiring schematic?
Which tab is which?

 

[FitchVA]

more info...
http://viewsfrommylens.com/Jeep/tech_relaybasics.html

 

[barillms]

What's the short yellow line from 30 to 87 for?
Is 86 a ground? ... Or MUST it go the the Neg. terminal?
The rest I understand. Thanks big daddy.

 

[5-90]

What's the short yellow line from 30 to 87 for?
Is 86 a ground? ... Or MUST it go the the Neg. terminal?
The rest I understand. Thanks big daddy.

Note its location in the schematic - it's entirely within the "outline" of the relay. Therefore, it represents an internal connection - in this case, it represents the internal contacts of the relay. You don't have to deal with it, it is simply meant to illustrate what happens when you turn the switch on.

As far as fusing, I would put a fuse in the line from the battery to terminal 30 (generally held to be "supply,") but you'd have a hard time finding the appropriate fuse to go inline to the switch. The relay coil draws, as I recall, about .05A - so I usually just don't bother.

Terminals 85 and 86 are either end of the actuating coil (not shown in these illustrations,) which is a simple coil of wire used as an electromagnet to "pull in" the contacts.

Terminal 30 (on pretty much all versions of the DIN/Bosch/Hella relay) is used as the "voltage/current supply" line, and you will usually see that terminal connected to the battery.

Terminal 87/87a is the "output" for the relay. If there are four terminals on the relay, it will be numbered 87, and will be a simple "on/off" unit.
If there are five terminals, it can go a couple of ways...
If there are two terminals numbered 87, it is a DPST relay (Double-Pole/Single-Throw,) which can be used to turn two circuits on/off at the same time.
If there are terminals 87 & 87a, it's a SPDT (Single-Pole/Double-Throw,) which may be used either as a simple "on/off," an "off/on," or a "changeover" relay. Either terminal 87 or 87a will be "hot" at any given time - but never both.

Make a little more sense now? If you go buy a DIN relay, you're probably going to get an SPDT, with terminals numbered 30/85/86/87/87a, unless you specifically ask for something else.

5-90

 

[FitchVA]

^ what he said. lol

 

[5-90]

^ what he said. lol

Sorry - I'm an engineer and a teacher by nature. Don't ask me a question if you don't have time for the answer - but it will be informative! :read:

5-90