After Run Pump Relay Needed
Printed From: the12volt.comForum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=138543
Printed Date: April 29, 2024 at 1:32 AM
Topic: After Run Pump Relay Needed
Posted By: fiat1980spyder
Subject: After Run Pump Relay Needed
Date Posted: February 21, 2015 at 10:49 PM
Replies:
Posted By: oldspark
Date Posted: February 21, 2015 at 11:19 PM
Posted By: howie ll
Date Posted: February 22, 2015 at 2:41 AM
Posted By: fiat1980spyder
Date Posted: February 22, 2015 at 7:28 PM
oldspark wrote:
Why do you want that? Are you having overflow or boil problems, or blowing headgaskets or other issues?
If not I wouldn't worry about it. As soon as the engine stops its combustion chamber begins to cool and that is the most temperature stressed engine part.
Other parts may heat up but that is normal and non damaging.
It's different with competition and non-(mechanical)-thermostat systems using electric water pumps but they merely need a timed circuit triggered by IGN off and optionally an initial kick-off thermostat (thermistor) enabling signal.
The vehicle is a 1980 fiat spider you actually have helped me through wiring a few items on it and relay questions i had in the past. They are very known for overheating or running a little hot, I have had a turbo on this car and also used a bigger aluminum radiator and made the cooling system a little better as well as a oil cooler but the engine still does suffer from a bit of heat soak. This system is implemented on the audi/vw turbo vehicles for many years and still use this to date, to improve the life of the engine/turbo. I would like to add this feature to help with the overall life of the components and reduce strain. Since posting i believe my best bet may be using a hella relay that way i have some adjust ability in time and NC and NO for how it is wired.
howie ll wrote:
Running a cooling fan with the ignition off will drain your battery in short order.
Yes it will but that's why i need a relay which has an internal timer set for 10 or 15min which will only turn on if the temperature switch is also above a certain temperature other then that it the fan and pump will not turn on. While putting a fan on 12v for 10 to 15 min and also a pump will possibly weaken a battery, this system uses a resistor to slow down the fan and just have it spin to cool as it circulates.
So i have looked at the diagrams and they are set up quite different and I am unsure what should be the input into the timer. I would presume that
terminal 15 is the ignition switch
terminal 31 ground
terminal 30 use the switch but instead of using + flip it to -
terminal 87A would ground the fan relay, afterrun pump
Also I would not use terminal 87
I would like to run a similar setup to the orginial,
The hella relay is set up in this configuration
The original fan relay uses a - input trigger for relay.
Posted By: oldspark
Date Posted: February 22, 2015 at 9:25 PM
Excellent! My apologies, as usual I did not note who the poster was 
and more often than not I see so many car projects like this that are so misguided or false. [Anyone for fuel polarisers; or mobile phone chargers to improve EMS & performance; or resistors - maybe even their hi-tech voltage-regulator version - to trick EMSs into better performance LOL (which would blow engines if they actually worked for leaner mixtures!)...? 
]
But cool - you said it - engine soak. And as I recall some of those Italians could suffer badly.
Incidentally, I suppose you have the normal crank driven water pump... you haven't removed the engine's (mechanical) thermostat and fitted an electric system?
If the Hella is a direct plugin for the fan relay (with added small terminal wiring) then I'd be tempted. My only concern would be if it draws current with IGN off - ie, from what I've seen such relays tend to use 555 timers and they have their 10mA standby draw. That's no problem for their fuel pump control relays (missing pulse aka tachometric 555 circuits) because they are powered via IGN +12V, but not seeing in the above relay schematic what timing circuit is used nor how it is powered after IGN off...
But I haven't examined your detail. I'd even have to look up whether 15 & 31 are IGN etc!
However I'd be tempted to use a DEI 528T or similar. That too has its 555 10mA drain but it should be easy having it power itself off tho that might require an extra relay (and 528T) if you want the fan to come on if whatever temp sensor hits your desired fan-on threshold within x-minutes of engine/IGN turn off.
My main attraction for the 528T is the use of available parts etc and the NON-use of specialised relays. (I prefer standard (SPDT) relays with external controls, even external quenching diodes etc.)
FYI - I'm looking at a similar 528T set up for bach939 in adding additional accessory to door locking. That's to use 528Ts but I need to check 555 (& 528T) trigger behavior wrt to power-on timing, etc.
Are you after stealth? IE - are you seeking originality in looks etc?
My solution to that was the use of a PICAXE 08 (08M2) which are 8-pin devices the same size as a 555 timer but without the need for larger timing capacitors etc. Excluding their output MOSFETs etc they could even be concealed within wiring - and reprogrammed without removal or direct access (run their programming input wire to somewhere suitable).
And the 08M2's standby current is far less than leakage current of automotive batteries so even fulltime powering is not an issue.
That does require the usual circuit construction ability (soldering etc) plus a serial interface & PC or maybe smartphone etc for programming plus the associated learning curve. However the latter is greatly simplified by the plethora of existing web projects (ie - copy & paste code) and once established is far easier than working with traditional circuitry... there is no need to overcome tricky electronic designs nor change or adjust componentry; just reprogram the new function or change parameters.
One standard 08M2 PCB or circuit can handle so many functions - ie include onboard LM7805 voltahe regulator (TO-92 package); 2 programming resistors; one MOSFET output; other inputs & outputs with provision for a series & pull up or down resistors & filter cap etc and a MOSFET for outputs.
IMO the 08M2 is perfect. It can be an add-on that uses the existing fan relay (probably without diodes if ground-switched sensors/controllers are used) and overcomes all problems... EG - switch or keep the fan on if whatever sensors are above a certain temp even with IGN off unless IGN has not been on for 5 minutes, and do not run for more than 3 minutes or if battery voltage is less than 12.4V... and BTW - flash that dash warning if the battery voltage is less than 13.4V with engine running else 12.6V & quicker if it's less than 12.4V (or get my battery monitoring program to text the dash's alphanumneric display next time the IGN key is inserted or turned on..).
That's merely a bit of brainstorming in case you are interested.
Otherwise it's back to traditional physical circuit implementations. And that's pending for me (I'm avoiding circuit DIYs like 555s & 08M2s for bach939).
and more often than not I see so many car projects like this that are so misguided or false. [Anyone for fuel polarisers; or mobile phone chargers to improve EMS & performance; or resistors - maybe even their hi-tech voltage-regulator version - to trick EMSs into better performance LOL (which would blow engines if they actually worked for leaner mixtures!)...? ]
But cool - you said it - engine soak. And as I recall some of those Italians could suffer badly.
Incidentally, I suppose you have the normal crank driven water pump... you haven't removed the engine's (mechanical) thermostat and fitted an electric system?
If the Hella is a direct plugin for the fan relay (with added small terminal wiring) then I'd be tempted. My only concern would be if it draws current with IGN off - ie, from what I've seen such relays tend to use 555 timers and they have their 10mA standby draw. That's no problem for their fuel pump control relays (missing pulse aka tachometric 555 circuits) because they are powered via IGN +12V, but not seeing in the above relay schematic what timing circuit is used nor how it is powered after IGN off...
But I haven't examined your detail. I'd even have to look up whether 15 & 31 are IGN etc!
However I'd be tempted to use a DEI 528T or similar. That too has its 555 10mA drain but it should be easy having it power itself off tho that might require an extra relay (and 528T) if you want the fan to come on if whatever temp sensor hits your desired fan-on threshold within x-minutes of engine/IGN turn off.
My main attraction for the 528T is the use of available parts etc and the NON-use of specialised relays. (I prefer standard (SPDT) relays with external controls, even external quenching diodes etc.)
FYI - I'm looking at a similar 528T set up for bach939 in adding additional accessory to door locking. That's to use 528Ts but I need to check 555 (& 528T) trigger behavior wrt to power-on timing, etc.
Are you after stealth? IE - are you seeking originality in looks etc?
My solution to that was the use of a PICAXE 08 (08M2) which are 8-pin devices the same size as a 555 timer but without the need for larger timing capacitors etc. Excluding their output MOSFETs etc they could even be concealed within wiring - and reprogrammed without removal or direct access (run their programming input wire to somewhere suitable).
And the 08M2's standby current is far less than leakage current of automotive batteries so even fulltime powering is not an issue.
That does require the usual circuit construction ability (soldering etc) plus a serial interface & PC or maybe smartphone etc for programming plus the associated learning curve. However the latter is greatly simplified by the plethora of existing web projects (ie - copy & paste code) and once established is far easier than working with traditional circuitry... there is no need to overcome tricky electronic designs nor change or adjust componentry; just reprogram the new function or change parameters.
One standard 08M2 PCB or circuit can handle so many functions - ie include onboard LM7805 voltahe regulator (TO-92 package); 2 programming resistors; one MOSFET output; other inputs & outputs with provision for a series & pull up or down resistors & filter cap etc and a MOSFET for outputs.
IMO the 08M2 is perfect. It can be an add-on that uses the existing fan relay (probably without diodes if ground-switched sensors/controllers are used) and overcomes all problems... EG - switch or keep the fan on if whatever sensors are above a certain temp even with IGN off unless IGN has not been on for 5 minutes, and do not run for more than 3 minutes or if battery voltage is less than 12.4V... and BTW - flash that dash warning if the battery voltage is less than 13.4V with engine running else 12.6V & quicker if it's less than 12.4V (or get my battery monitoring program to text the dash's alphanumneric display next time the IGN key is inserted or turned on..).
That's merely a bit of brainstorming in case you are interested.
Otherwise it's back to traditional physical circuit implementations. And that's pending for me (I'm avoiding circuit DIYs like 555s & 08M2s for bach939).
Posted By: fiat1980spyder
Date Posted: February 23, 2015 at 9:16 PM
Posted By: Ween
Date Posted: February 23, 2015 at 10:33 PM
Posted By: oldspark
Date Posted: February 24, 2015 at 3:22 AM
Posted By: fiat1980spyder
Date Posted: February 24, 2015 at 9:58 AM
Posted By: howie ll
Date Posted: February 24, 2015 at 10:23 AM
Posted By: fiat1980spyder
Date Posted: February 24, 2015 at 5:27 PM
Posted By: howie ll
Date Posted: February 24, 2015 at 6:13 PM