Bob Nichols <bocd@optonline.net> wrote:
: Jon...
: Thanks for thye reply....I ordered an extender today for 45.00 and am
: going to stop and get a relay today.
: With all of the wiring I've done...I never used a relay
Yep, I like relays. :-) Not only because they allow you to use
a small current wire to control a large current, but you can also do
some cool stuff with them when you start wiring a bunch together;
especially if you throw some of the 5 pin relays in there too; you
can essentially build little mechanical computers out of 'em, I like
to think of them as being able to give an inanimate object just a
*touch* of intelligence. :-) Anyhoo...
: Thanks for all of the detail !
Sure thing! As far as the relays go, for your application, all you
need is a 4 pin, but a 5 pin will work too. The package the relay comes
in will probably have a schematic on the back showing how to wire it up,
but just in case, the pins will usually be labeled 85, 86, 30 and 87. If
its a 5 pin relay, there will be an additional pin labeled 87a. In your
case, you would run pin 30 to the positive terminal on the battery (
preferably via an in-line fuse), pins 85 and 86 are the "control" or
"coil" pins, this is where you hook up the wire you want to use to turn
the relay on and off. One of the pins is hooked to ground and the other
to the +12v wire you want to use under the hood to tell the relay when
the ignition is on. It doesn't matter which pin is ground and which is
hooked up to the control wire. Pin 87 would run to your inverter, this
is the pin which is switched on and off when the coil inside the relay
is energized. In your case, if you get a 5 pin relay, you'd just ignore
pin 87a, but basically its function is the opposite of pin 87; when the
coil is energized, pin 30 is internally connected to pin 87; when the
coil is not energized, pin 30 is internally connected to pin 87a. (So,
if you do get a 5 pin relay, be sure to put some tape or something on pin
87a to insulate it because it will have full battery voltage on it whenever
the ignition is off.)
As far as hooking up the relay goes, you can either buy a mounting socket
that it plugs into, or you can just connect .25" female spade terminals
directly to the male terminals on the relay. If using non-insulated spade
terminals for this, I like to put some heat shrink tubing on them or at
least a couple wraps of electrical tape in case something metallic gets
up in there or the pins get bent and try to short out. You'll probably
want to try and protect the relay from the weather as much as possible,
as they can corrode. If its open to the elements, expect to have to
replace it every few years, depending on the type of weather the truck
sees.
A thought just occured to me - if you wanted to get really fancy,
I'll bet you have an unused relay plug in your PDC, for an option that
didn't come on your truck, like maybe 4 wheel ABS or AC or whatever. If
so, you could technically wire it right into the PDC using that unused
plug, pop your relay into the PDC, and it'd look factory. Plus, your
"trigger wire" will probably be coming from the PDC somewhere, and
you can probably get a ground in there too. Anyhoo, was just a thought;
maybe that won't work in your particular case, but might be worth
checking into.
Have fun! :-)
--
-Jon-
.-- Jon Steiger ---- jon@dakota-truck.net or jon@jonsteiger.com --.
| 1970 Barracuda - 1990 Dakota 'vert - 1992 Ram 4x4 - 1996 Dakota |
| 1996 Intruder 1400 - 1996 Kolb FireFly - 2001 Ram QC 3500 CTD |
`------------------------------------ http://www.jonsteiger.com --'
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