those metal can relays are not available anywhere i have been able to find and not necessary. the standard plastic can ones are fine. i know there are lots of feelings about name brand vs non name brands and you have to decide yourself. i ordered some hella relays and they were made in china.
the relay you need is a SPST single pole single throw. 30 or 40amp will be fine. you are not drawing lots of power. they are under ten bucks at any auto store.
it is a 4 pin relay. in the new relay configurations the pins are labeled the same for all manufacturers. they as follows. you only need a 4 pin relay so 87a will not be on it. if it was on it, you just wouldnt hook it up. so it can be used if needed.
not to confuse you, but there is another config that i used on my headlights. it is a dual 87 relay and it gives you outgoing power to 2 loads (left and right headlights in my case) without splitting the wire. they are not usually avail at autoparts stores.
so, at autozone or checker or napa or whatever autoparts store. just get a SPST 4 pin relay with NO diodes or resistors. it will tell you if it has a diode or resistor on the packaging.
autozone has several ones.
the pinout of the new relay is
-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)
-87a = [on 5 lead/pin relays only] this lead/pin is connected to lead/pin 30 when the coil is NOT powered.
here is the bottom view of a standard 4-lead Bosch-style automotive SPST relay
here is what happens inside the 4-lead/pin SPST relay. on the left, the coil is NOT powered. on the right, the coil IS powered. notice the switch changes positions when the coil is powered. when the coil is powered, pins 30 and 87 are connected. when the coil is NOT powered, then pin 30 is not connected to anything, therefore it is in the 'off' position.
i figured i would show this for those who dont have alot of experience with relays. they are quite simple and easy to use. the reason for them is simple. if you are running alot of current, it is really hard on switches. so you let the relay handle the high current and you use your switch power the relay and it takes very little power to turn the coil in the relay on and off preserving the contacts on the switch. a good example is headlights. on my 1990 newell wired them up directly from the headlight switch. i added relays to take the heat off of the switch. my 2002 had that done alreday (though with the smart wheel is wired quite strangely).
there are basically 3 configs of relays commonly used. a 4 pin that switches one leg to one output. a 5 pin that provides two switched outputs (dual 87, like used on headlights), and a 5 pin that has an 87 and 87a output. the 87a is normally closed allow power to get through all the time and 87 is only powered when the trigger is switched). you can use this relay in place of the 4 blade one and just NC (no connect) the 87a.
hope this wasnt confusing.
tom
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