Sorry, I know this is a modding forum (which I love and participate in) but I figured you guys would know better than anyone how to wire up a simple switch. I have an electric water pump in my car that turns on when the ignition turns on via simple bosch relay. Basicly when it senses the ignition it flips the internal switch and runs the pump. My problem is I'm trying to wire it up to run off a switch when the vehicle is off so it can cool down between runs at the track. I contacted the water pump company (meziere if it matters) and they were very helpful. This was his response. As far as the wiring question, it's pretty easy to do what you want but you will have to understand how the pump was originally wired. There is a trigger wire right now that tells the relay when the ignition is on. Yo u will need to interrupt that wire with a switch that has 3 poles on the back and two positions for the actual toggle. The original wire will connect to one side of the switch and a constant 12v to the other side. The center pole will then go to the relay. The idea is to trick the relay. With the switch in one direction it will receive a 12v source from the "ignition on" state and with the switch in the other position it will receive the signal from you (flipping the switch to supply 12v). I hope that's clear. If not, just give a call and my tech guy can clarify. Don Meziere Meziere Enterprises Inc. So it sounds easy enough. I went out and bought a switch with three poles on the back like he said. Which looks like the switch he described, but on the back I saw this. Now its showing a power, load, and ground as the correct way to wire this. But thats not what I need! Any help on how to wire this switch or pointing me in the right direction as far as what switch I need would be appriciated!. Please reply as soon as possible, I have to put this together before tomorrow (track day) Thanks a ton.
Unfortunately, that is the incorrect switch you need for your job. That switch is misleading, due to one small detail, it has an indicator on it. The ground connection is used for nothing other than to provide a return path for the LED indicator. This is a SPST (single pole, single throw), which means, it only provides to contact points, and either connects them, or disengages them. What you need, is a SPDT (single pole, double throw), which has an A and B, and a common. The common you would tie to the relay, the A to the ignition switch, and B to constant power. This switch then has two positions (sometimes three, if it's an on-off-on, type of switch). If you look at this page: http://www.kpsec.freeuk.com/components/switch.htm The one you need is labeled as "ON-ON" or "ON-OFF-ON." Hope this helps.
Thanks! To bad I liked the looks of those switches. Looks like I'm going to have to order something PS any ideas where to get a nice looking switch that would compliment a nice cars interior? The ones in the picture I liked because they looked somewhat stock.
would one of these two work? I think the idea of having a key to make sure nobody kills my car is a great idea! Also, after I get the water pump worked out I'm going to wire the electric fan up the same way. Would I damage anything *in you opinion* by using the same switch for both? http://www1.mscdirect.com/CGI/N2DRVSH?PACACHE=000000016319292 This is the car its going in by the way.
The link in your post doesn't work for me. I'd think that any of these would work: http://www.allelectronics.com/cgi-bin/item/RS-146/700400/SPDT_CENTER-OFF_ROUND_ROCKER_SWITCH_.html http://www.allelectronics.com/cgi-bin/item/RS-116/700400/SPDT_ON-OFF-ON_PADDLE_SWITCH_.html http://www.allelectronics.com/cgi-bin/item/RS-131/700400/SPDT_CENTER-OFF_ROCKER_SWITCH_W_DIODE_.html http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=060-315 You could even try some of these: http://search.ebay.com/search/searc...action=compare&copagenum=1&coentrypage=search If the electric fan also uses a relay, then you should be able to use the same switch for both. On the common terminal of the switch, just connect both the fan relay coil and the water pump relay coil to it, and the one switch would control both in a manual or auto mode (also off, if you get the on-off-on type of switch). I saw a photo of a rocker switch that was labeled on the switch, ON OFF AUTO, which looked nice, but couldn't find one online.
I'm looking for an on-on switch so Its impossible to actually run the car without the fan/pump running. Sorry about the bad link. Let me try this one for you and see what your opinion is.
I think that would do it. Good point, wouldn't want the car running without the water pump, huh? LOL.
quick question. I already have the switch in the picture and I like the LED indicator. Could I use a DPDT relay to do the same thing he mentions doing in the email, just using a relay instead of a switch. I would use the second set of contacts on the relay to do the same thing to the electric fan. The way I understand it a DPDT allows you to use one control circut to control 2 seperate items? Both of which will be connected in one configuration or a nother when the switch is off or on. IE.. with the toggle switch not turned on the relay would allow the fan and pump to work as they are wired now. When I flip the switch it will bypass it and go directly from 12v. Sorry if this is elementary but its my first attempt to use a relay.
Yes, that should work as well. You could then use the switch that you currently have, with the LED indicator. The wiring gets a little more complicated, but not that bad. Basically, you would run the power from your switch, to constant 12V, the load to the coil on the relay, the other end of the relay coil to ground. Then, the common of each side of the relay goes to the fan and water pump (respectively), and the NC (normally closed) terminal of each side of the relay goes to ignition 12V and the NO (normally open) terminal of each side of the relay goes to constant 12V.
Just one more question and I'll leave you alone geogecko Look at the very top right of this picture, its listing the pins by #'s Now, I ran power from the 12v battery to my switch then the other end of that goes to number 7? Then I ground number 8? hope thats right. Now you said the common of each side of the relay goes to the fan and water pump, which pin are the commons?? And which 2 are normaly open and which are normaly closed lol. And how in gods name do you know this
LOL, yes, that's right, 12V from battery, to switch, to pin 7 on the relay, then pin 8 goes to ground. That completes the coil activation circuit. That is one strange relay schematic, if I say so myself. Based on the picture, pins 5 and 6 are the commons, this is because, these two pins can either connect to 1 & 3 or 2 & 4. Now, the hard part, is determining which is NO and which are NC. Normally, the way this is shown, is the NC contact will be making connection with the common in the drawing, which from what I can tell, looks to be pins 1 and 2, but the arrows are so close to each other, it's hard to tell from the picture. Do you have an ohm meter or voltmeter at all? If you have an ohm meter (you can get a nice cheap one at Radio Shack for about $20, which is handy to have around--I like the small pocket sized one, that has a lid to store the probes in), put it on the ohms setting, and touch the probes to pins 1 & 5. If you read a short (close to 0 ohms), then that is the normally closed contact (pin 1), if it's open (high ohms), then it's the normally open contact (pin 1). If you ohm out pins 3 & 5, this should be the opposite of pins 1 & 5. So, from there, you want pin 5 going to the fan and pin 6 going to the pump, or vise versa. Then if you hook up the NO and NC connections as described in my last post, when the switch is off, the ignition will control the relays, when you flip the switch to on, the switch controls them manually. Also, don't forget the ground on the switch, so your LED works!
