dual switch circuit diagram

Hey guys,

i want to hard wire in my compressor but have a switch at both the back and front of the vehicle. Does someone have a basic wiring diagram that would achieve this so that either switch can turn on or off the compressor. I gather I need a special sort of switch that will active on which ever side of the switch is selected.

I was fine wiring up harnesses for spotties and such but trying to put two switches into the loop I wasn't sure.

Cheers,

Garrick

They just need to be in parrallel mate. Whatever you have as a switch wire make the same to both, and then the "neutral" side of the switch connects back to the same point as well. I will make up a dodgy drawing for you in a minute.

Mitch

Here ya go mate, hopefully you understand, if not just ask a question. They dont need to split at the first switch, they can seperate at the battery for what it matters for the incoming side of the switch.


Mitch

i would wire it up like the following diagram, that way you get complete on/off control from both ends of the car, regardless of the state of the other switch.

simonk8 said:

i would wire it up like the following diagram, that way you get complete on/off control from both ends of the car, regardless of the state of the other switch.

Click to expand...

The way you have put it up will also work, as will my way. Yours just uses a SPDT switch. The reason i did mine was cause it's easier when using a simple on/off switch. Both ways will work.

Also with yours the switches may be in a different position for on/off after use. this may not worry some people, i just know with me that i have them all ALWAYS in the same position for off and on, just to remind me a bit easier.

Mitch

If you use a couple of Single pole double throw switchs it will turn on or off at both switchs.(like a hall way light with a switch at both ends)
This will require you to run two wires between the switchs. (prob best to use some figure 8 cable)

where is the compressor mounted and what sort?
I would run it thru a heavy duty relay and just use the switches at either end of the car to switch the earth pole on the relay.
That way you do not have big lengths of positive cable running everywhere.

All depends where the compressor is to be mounted and how far away from power source.

If you use Simonk8's diagram (it's similar to Brad's) and have the one cable run heading down to the back you'll have a simple "hotel switch" system. Doesn't matter which end you stand, flick the switch it turns on, walk down the other end flick the switch it turns off.

It requires 3 wires (2 positive, 1 negative) and considering the current required to turn a compressor over I'd look at 8sqmm cable at least, 10sqmm would be even better.

The relay idea isn't a bad one. If you want the switches inside (not under the bonnet at one end of the cable and in the tub at the other) then I'd consider the relay. Best way to do the relay is to use Simon's layout but use lighter cabling (4sqmm stuff would work fine) from the power to the switches and on to the relay, and have the heavy stuff direct from the battery to the relay's contact terminals. Where does the relay go, electrically? Between the last switch (Switch 2 in Simon's drawing) and the compressor.

I would use a relay for the compressor as they are fairly high load items, you will need a too big of a cable, you can wire the switching as a two way but I wouldn't bother; 1- you'll be limited as to the availability of two way switches, probably end up with the type you would have in a house. 2- Do you really need to turn on at one end and off at the other.
I'd just put one switch at the compressor as you have to go there to plug the hose on anyway, unless you are using it for a locker of course

Thanks guys. Great help. So as I have it i need two SPDT switches and a relay. I modified one of the diagrams above. It seems logical? The reason for the switch at either end is i'm gonna have two hose connections, one at each end.

Looks good to me.

yeah that will work