Timed Switches... Send me to school

[D_Fresh361]

working on a project that is having some heat soak/temp rise after the engine has been cut off leading to hot start issues.

Plan is to install an electric fan to aid in cooling after the coolant system and flex fan or no longer able to do their job.

My question to y’all, is there a toggle style switch that is timed? Apply power, walk away and switch cuts power after set time, what that may be preset or whatever.

What do I need here? Don’t really want to go the sending unit route that operates off of temperature/on - temperature/off.. is this my only option?

Thanks for any input.

 

[dgr]

Push button switch
Delay on break timer
Done

 

[nj_m715]

find and fix the hot start issue?

 

[Thewespaul]

Is it the mustang? If so its probably just your starter getting heat soaked with your headers if its not cranking fast after heat soaking. Put a mini starter on or a heat blanket, had that exact issue with a big block ford and headers.

 

[IDIBRONCO]

had that exact issue with a big block ford and headers.

That's why 429s and 460s had a second solenoid on thee starters. Similar to an IDI.

 

[D_Fresh361]

Is it the mustang? If so its probably just your starter getting heat soaked with your headers if its not cranking fast after heat soaking. Put a mini starter on or a heat blanket, had that exact issue with a big block ford and headers.

Indeed it is. I will check into this. Thanks for the direction man

 

[raydav]

My question to y’all, is there a toggle style switch that is timed? Apply power, walk away and switch cuts power after set time, what that may be preset or whatever.

My turbo is remote mounted on the frame. I have a scavenge pump to return the oil to the engine.

I made a turn off delay for it. Turn on "ignition", the pump starts. Turn off, and the pump stops a minute later. The pump is controlled by a power transistor. The delay circuit is just a resistor, diode and capacitor.

 

[dgr]

... The pump is controlled by a power transistor. The delay circuit is just a resistor, diode and capacitor.

Student:. Where will I ever use math?
Raydav:. Watch this
This is a very cool solution. Does the pump also take the cap charge time to turn on when you start the truck?

 

[raydav]

Student:. Where will I ever use math?
Raydav:. Watch this
This is a very cool solution. Does the pump also take the cap charge time to turn on when you start the truck?

No, it is kinda like a check valve; instant turn on and slow turn off. The cap is charged thru the diode and bleeds off thru the resistor.

And it is slightly more involved than I said. I did this years ago and kinda forgot. There is a small transistor, diode, resistor and cap that form the turn off delay, and that drives a large buffer transistor.

You must be registered for see images attach