change 2 toggles to one rocker switch

I have a wiring question on some solenoid valves i am wiring up. It is for the waste vegetable oil setup I am installing on a F150. I want to combine the two toggle switches into one two or three position lighted rocker if i might. T1 is the power that actuates the first two solenoid valves directly and sends power to a timer relay shown on the right side of the schematic. T2 controls the 12 volts out of the timer relay for a forced shutdown. It needs to be a forced shut down because it also powers the fuel (diesel) solenoid on top right of the drawing. In MOST cases i will simply flip the switch(s) to on position. The dilemma is this: T1 should never be on without T2 being on. T2 can be on without T1. The T2 switch would be the forced shut-down switch that would terminate power to the fuel solenoid. The delay timer is to allow purge of the oil in the fuel system. It will keep waste oil from returning into the stock diesel tank and allow the engine to run and keep ONLY the return valve actuated during shutdown for the set time delay. The problem is there will be occasions (short stops for less than two hours) when i don't want to go through purge and the whole system would need to be shut off. I can run it with two switches, but i want it as idiot proof as i can make it for others who may drive my truck. I really would like a lighted rocker that has two indicator lights. One that would be on when in the on position and another that would be on when WVO is in operation. I have heard of using a rocker and "crossing it over" to accomplish what I want to do, but i'm not sure how to accomplish this. Thanks.

I think you might be able to get away with an on/off/on DPDT switch with some trick wiring. However I need to be clear..you want to be able to have both off, both on..and T2 on by itself as the only options? BTW I installed a couple of WVO systems and one on a Ford F-250. Worked great for years, still going as far as I know.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

quark kent wrote: I think you might be able to get away with an on/off/on DPDT switch with some trick wiring. However I need to be clear..you want to be able to have both off, both on..and T2 on by itself as the only options? BTW I installed a couple of WVO systems and one on a Ford F-250. Worked great for years, still going as far as I know.

That is correct. T2 on with T1 off would be on the occasion of a normal shutdown where I would exit the vehicle and the engine would purge and run at the same time for the set time of the relay.

Okay yes I remember we had to do that with the truck and cars I installed it on too. I am thinking a DPDT on/off/on should work. You could wire one side to power up T1 and T2, and the other just to T2..and one position both off. I suggest you google DPDT lighted switches and see if you can find on that has dual light (one for each "on") and that should do it. Without it in front of me with a meter and the fact that I never did it that way before I can't give you a proper diagram but essentially two terminals on the switch should be feeds (inputs) and you can use one position to power both and the other output independant to power T2 alone. (assumeing the switch has internal isolation) The 3rd position will just cut power to both. The only concern might be backfeed and that could be isoloated with diodes or perhaos a relay if the current demands are more then a 1-3 amps but this depends on the switch as well.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.

If what you want is T1 controlling something and T2 controlling something else where either position can control common things, then an SPDT (or DPDT) center-off with diodes from each on terminal to respective targets (line end towards target if it's a +12V switch). That allows you to turn on any combination with either of the 2 positions without feeding back into undesired targets.

oldspark wrote: If what you want is T1 controlling something and T2 controlling something else where either position can control common things, then an SPDT (or DPDT) center-off with diodes from each on terminal to respective targets (line end towards target if it's a +12V switch). That allows you to turn on any combination with either of the 2 positions without feeding back into undesired targets.

I have a DPDT on off on rocker with a single light. There's 3 prongs on one side and 4 prongs on the other side. Not sure how to wire it up. Any suggestions on a schematic.

Generally that extra 4th one on one side is negative for the light in the switch. The center terminals should be for your 12v+ feeds and each one above it is 12v+ out for switch position on 1 and the others below are for switch position on 2. If unsure you can use a small light bulb and a 9-12v battery or DC power supply to test it. When hooking it up make sure to use a fuse no larger then the current rating of the switch. If the circuit draw exceeds the rating of the swtich you will need a higher current switch or use relays.I can not explain to you what "nothing" is in a scientific way. What makes matters worse is you won't notice it when you finally have the opportunity to experience it.