ThreePointFive Posted April 29 Share Posted April 29 Contrary to the title, this is not about one of @Mo Murphy's grotty beer-fueled rendevous. I have a 3 way switch (off-on-on) which controls my fans - off is,well, off... on 1 is thermostat control, 2 is manual override. I want a buzzer/alarm when the fans are off so they can't be forgotten . Also, as the switch is located on the right of the steering column, it's possible for me to press the button with my knee. But I can't find a 3 position 'on' switch, just the one I have. Does anyone with intimate knowledge of the Carling catalogue know if one dose exist? They've hugely expanded their range and finding anything is now stupid. If not, I'll get the two position on-on switch and just pull out the fuses if I am ever going to need to wade. I don't make a habit of it so highly unlikely. Mods, no idea where to post this so move if inappropriate. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 29 Share Posted April 29 You could connect two diodes to the 'on' outputs, and connect them to to the trigger of a relay. Then use the NC connection in the relay to power the buzzer. When the switch is in either of the on positions, the relay will be triggered, turning the buzzer off. Make sure relay is powered by ignition live though 2 Quote Link to comment Share on other sites More sharing options...
bishbosh Posted April 29 Share Posted April 29 14 minutes ago, Bowie69 said: You could connext two diodes to the 'on' outputs, and connect them to to the trigger of a relay. Then use the NC connection in the relay to power the buzzer. When the switch is in either of the on positions, the relay will be triggered, turning the buzzer off. Make sure relay is powered by ignition live though Umm, English please???? 2 Quote Link to comment Share on other sites More sharing options...
elbekko Posted April 29 Share Posted April 29 Check here: https://www.carlingtech.com/sites/default/files/documents/V-Series_datasheet.pdf At a glance I'd say "no, doesn't exist". But there are some of the "special circuits" listed that might work? 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 29 Share Posted April 29 7 minutes ago, bishbosh said: Umm, English please???? Elementary, my dear Charles. 1 1 Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted April 29 Share Posted April 29 2 hours ago, bishbosh said: Umm, English please???? You are not alone......... Regards Stephen Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted April 29 Share Posted April 29 Depending if it's high side or low side switched you can do this as Bowie suggests - in short, if you wire the buzzer across the switch so that in 1 of the 2 "on" positions the switch is shorting out the buzzer, when the switch is "off" the buzzer (being quite low power) will be powered by the voltage between the open switch contacts. I've not thought deeply about it but I suspect wiring it from the switch common to the AUTO input would work. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 29 Share Posted April 29 Call MudStuff UK - they sell the switches and, as a business dedicated to modifying Land Rovers, would be more likely to help than other Carling vendors. 1 1 Quote Link to comment Share on other sites More sharing options...
Popular Post ThreePointFive Posted April 29 Author Popular Post Share Posted April 29 While waiting for my electrical engineering degree so I can follow Bowie's answer and understand Fridge's supporting comment, I decided to call MudStuff. https://www.mudstuff.co.uk/products/carling-on-on-off-switch?_pos=1&_sid=43b786304&_ss=r Good news! This is an on-on-on switch, they just advertise it as on-off-on to meet most peoples' use case. Gooder news! I already own one and it's the one in the car... Better still, they have instructions via that very link on how to wire it up in on-on-on state. Sincere thanks for all replies across the technical complexity spectrum. 5 1 Quote Link to comment Share on other sites More sharing options...
forkrentfitter Posted April 29 Share Posted April 29 off on on is used on jcb telehandlers, let me know if i can help. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 30 Share Posted April 30 18 hours ago, ThreePointFive said: While waiting for my electrical engineering degree so I can follow Bowie's answer and understand Fridge's supporting comment, I decided to call MudStuff. https://www.mudstuff.co.uk/products/carling-on-on-off-switch?_pos=1&_sid=43b786304&_ss=r Good news! This is an on-on-on switch, they just advertise it as on-off-on to meet most peoples' use case. Gooder news! I already own one and it's the one in the car... Better still, they have instructions via that very link on how to wire it up in on-on-on state. Sincere thanks for all replies across the technical complexity spectrum. I have a few of these and would like to do as you are when I change the allocations of the seven Condura switches on my panel. Would you mind sharing the wiring configuration they sent you, as I didn’t notice a method of connecting them for that purpose. Thinking about it rationally, having the battery feed into the regular position and the first output (live in both on positions) to the relay live feed and the second on position (only live on the final switch position) to the relay trigger terminal in parallel to the thermostatic switch would work. The switch indicator light might be an issue, though, as it would be lit when the mid position is on but the fan is not running. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 30 Share Posted April 30 55 minutes ago, Snagger said: Would you mind sharing the wiring configuration they sent you, as I didn’t notice a method of connecting them for that purpose. The wiring specs are on that page, lower down 1 Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted April 30 Author Share Posted April 30 23 hours ago, forkrentfitter said: off on on is used on jcb telehandlers, let me know if i can help. That's kind, thanks. I'll have a bash but I don't think it's going to be simple due to the way I've wired in the fans. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 1 Share Posted May 1 12 hours ago, ThreePointFive said: That's kind, thanks. I'll have a bash but I don't think it's going to be simple due to the way I've wired in the fans. If you can get the crayons out and draw a diagram of how you've done it we can offer helpful suggestions that you may or may not understand 1 1 Quote Link to comment Share on other sites More sharing options...
elbekko Posted May 1 Share Posted May 1 Sort of on topic. I've been on the hunt for a simple solid-state inverter (NOT gate) for 12V. I actually found one on RS, ordered it, then realised the entire thing is smaller than the tip of my soldering iron Would be nice to just have a little off the shelf component that you could throw into a circuit like that without having to worry about a relay's power draw and size. And obviously, googling "12V inverter" is hopeless. 1 Quote Link to comment Share on other sites More sharing options...
Peaklander Posted May 1 Share Posted May 1 (edited) I have two of those switches and use them for two different interior light circuits, linked in with the 10AS for normal operation. So that's Off-Door-On. It is a double pole switch and with the three positions, it is complicated. The hardest was working out the connections, as Mudstuff tend to explain how to, rather than what. I found the pin layouts on a Carling page (here) and shown in my diagram. A key bit is that internal connection off pin 3 which is made in the two ON ON positions. The other more useful feature in your case is that pin 4 is connected internally at both the OFF and first ON position (not shown in the diagram) and that's why the Mudstuff linked page (here) says link 2 to 4. That then means that 5 is power in and 1 is power out in the usual OFF position. That might help🤔 Edited May 1 by Peaklander clarified pin 4 internal connection 1 Quote Link to comment Share on other sites More sharing options...
ThreePointFive Posted May 1 Author Share Posted May 1 12 hours ago, FridgeFreezer said: If you can get the crayons out and draw a diagram of how you've done it we can offer helpful suggestions that you may or may not understand I'll be sure to draw some lines on diagrams but just to show the level of sheer jank I'm dealing with... I think you can tell this was pretty much the last thing I wired up before geting it back on the road. I normally wouldn't show how thrown together the thing is, but this is exceptional. When I can muster the brain cells, I'll sort out the diagram and go from there. Initial investigations have resulted in the fans being perma-on, so I think the answer to that comes from reading Peaklander's post carefully. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted May 1 Share Posted May 1 In position A you want alarm on and fans off. In B you want alarm off and fans on thermostat and in position C, alarm off and fans manually on. So maybe this would work… Pin 5: power in link pins 4 to 2 Pin 1: out to alarm / switch in position A Pin 3: fans on thermostat / switch in position B (middle) Pin 6: fans on manual (but thermostat output is on also) / switch in position C …can you handle position C with the fan thermostat output on together with the manual output? If that’s good then it’s ‘just’ the two leds to sort. 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 2 Share Posted May 2 I used to have my fans on a standard DPDT on-off-on switch, that was easier to wire so that the centre position was "off" and it was one way for auto and the other for always on, the same may be true for the carling. Quote Link to comment Share on other sites More sharing options...
Escape Posted May 2 Share Posted May 2 The correct diagram for the off-on-on supplied by Mud etc is E. With the link between 2 and 4 to be externally added only if required. I's use the wiring as described by @Peaklander. But I don't think the thermostat will be powered in C, because there is no connection between 5 and 4, so no power to 2 and 3 for the thermostat. It wouldn't matter anyway, as it's the same 12V. I have wired the electric fans in my Lotus in a similar way (without the off and warning), normal operation controlled by the thermostat but with the option to override on manual, wired in parallel. I've used several of those off-on-on switches in different ways when rewiring my P38. Wonderful things those Carlings, but it can get complex if you have a dozen or so to wire side by side. 2 Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted May 2 Share Posted May 2 23 hours ago, elbekko said: Sort of on topic. I've been on the hunt for a simple solid-state inverter (NOT gate) for 12V. I actually found one on RS, ordered it, then realised the entire thing is smaller than the tip of my soldering iron Would be nice to just have a little off the shelf component that you could throw into a circuit like that without having to worry about a relay's power draw and size. And obviously, googling "12V inverter" is hopeless. Wouldn't a suitable pFET do what you want? Insert it in the high side of your circuit. Pull up resistor on gate to 12V. Apply 12V to gate and FET is open circuit so no power downstream. Pull it low to ground and FET starts conducting allowing power through. I'd add some snubber caps on the gate to protect it from transient but the principle is there. Quote Link to comment Share on other sites More sharing options...
elbekko Posted May 2 Share Posted May 2 24 minutes ago, Ed Poore said: Wouldn't a suitable pFET do what you want? Insert it in the high side of your circuit. Pull up resistor on gate to 12V. Apply 12V to gate and FET is open circuit so no power downstream. Pull it low to ground and FET starts conducting allowing power through. I'd add some snubber caps on the gate to protect it from transient but the principle is there. Probably, yes. I'd just like it in a small pre-made package that I can easily hide in a wiring loom. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted May 2 Share Posted May 2 Ah yes, @Escape shows the correct diagram. Sorry about that. It shows the necessary external connection between 2 and 4. Those other switch positions do make the connections as shown. I use it on OFF ON ON with 5-6 and 2-3 made at OFF, then 5-4 and the external link feeding 2-3 in ON#1 and then 5-4 and link feeding 2-1 in ON#2 Quote Link to comment Share on other sites More sharing options...
Snagger Posted May 2 Share Posted May 2 At the moment, I have a thermostatic switch and a simple off/on switch in parallel to the fan relay. The thermostatic switch’s lower temperature outlet terminal is the one wired in. I intend to fit a dash warning bulb to the higher output. Could you do the same? It doesn’t seem important to have the fan powered unless the temperature is getting problematic, so a simple warning should suffice. I do intend to move the dash control from that off/on switch to a Carling switch on the dash (bit of a remodel to come), hence my earlier question. I plan on having a similar off/auto/on choice like you. What I would like to do is have the auto position in the uppermost position, on in the mid position and off at the bottom. That way, the natural position for the switch would be up, in auto, and the most unnatural position to leave the switch when exiting the car would be fully down, in “off”. The problem with the switch with basic wiring is that the middle position has one live output and the second on has two, which is not how I’d like it - I’d rather have two in the middle so the relay feed and its trigger terminals are both live in that position, and have the top switch position have only the relay feed live (so the relay trigger is only from the thermostatic switch), and the relay isolated in the bottom position. I don’t know if that is going to be possible. The switch lends itself to having the automatic position in the middle. Maybe instead of using the switch and thermostatic switch in the positive feed to the relay, using it in the earth of the relay would be better, one wire running directly from relay earth terminal to the Carling switch and the other via the thermostatic switch to the other gang of the Carling switch, earthing to the dash via the terminal usually used as a live feed? Quote Link to comment Share on other sites More sharing options...
Peaklander Posted May 2 Share Posted May 2 (edited) 4 hours ago, Snagger said: The problem with the switch with basic wiring is that the middle position has one live output and the second on has two, which is not how I’d like it - I’d rather have two in the middle so the relay feed and its trigger terminals are both live in that position The OFF ON ON switch does have two live terminals in the middle position and at one end. In the diagram it shows one position as normally closed (solid lines 2-3 and 5-6) and the other two as dashed. So you can work it out. Also the tip mentioned already, that you can jumper from the switched position at pin 4, means that the common contact at pin 2 can be driven by switch position, rather than a direct feed from something else. 8 hours ago, Escape said: Also if you rotate the illuminated front plate, I think you often you lose the green dash illumination as the led, is no longer behind the diagram part. I might be wrong about that as it's been a long time since I constructed my switch panel. Edited May 2 by Peaklander 1 Quote Link to comment Share on other sites More sharing options...
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