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Tips
Tips

Timer for pusher fan

warwick-steve

Jedi Hopeful
Offline
Hi
I have fitted an electric pusher/blower fan with a on/off switch for when I am in slow traffic and for when I turn the engine off. Is it possible to fit some kind of 12v timer into the circuit so that when I park up and walk away from the car the fan will switch off after a preset time? Any one know of a suitable timer?
Thanks
Steve
 
[h=1]Derale #16759 Adjustable Fan Controller. A good one. Available @ Amazon, Summit Racing etc. Works like a charm. I replaced 3 or 4 cheapos until this one.[/h]
 
Steve,

My TR7 had Air Conditioning with a heave York compressor. Seeing little use for this old system, I removed all the air conditioning components as well as the puller engine-mounted fan from under the hood and left the 2 auxiliary fans. These auxiliary fans were mounted on an upward angle in front and below the radiator so as not to block air movement through the radiator when the car is moving forward. Additionally, and specific to your objective, these fans are thermostatically controlled (on and off) with a sensor on the upper tank of the radiator.

As I remember, there is a plug on the bottom of the top tank of the Healey's radiator. If you can get an adjustible thermostatic switch that can be made to fit into that opening, you can adjust the control to start by a set temperature or manual switch and automatically turn off when the engine temperature drops to a set temperature.

Just a thought,
Ray(64BJ8P1)
 
Last edited:
This what I’m going to be doing to replace the first setup I did.
 

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Steve
i am in the process of adding a pusher fan to my car and thought i remembered reading this thread.
The Beuler BU508TD timer relay might be what you are looking for. i am going to give it a try.
 
Hi Drone Dog
Thanks for the info.
I have just purchased a Kemo 12volt Time switch which incorporates a relay which is wired into the fan circuit. It can be switched on using a small button and switched off using a second button. Alternatively it can be switched off using the built in timer. The delay time can be adjusted between 2 seconds to 23 minutes. The timer and the two button switches including delivery from Germany was about ÂŁ15.
cheers
Steve
 
Steve
i am in the process of adding a pusher fan to my car and thought i remembered reading this thread.
The Beuler BU508TD timer relay might be what you are looking for. i am going to give it a try.

This forum discusses this. One scenario they discuss is fitting a momentary switch so you can trigger the 2 minute relay when you want to rather than automatically. Seems like there would be many times where the car wasn't hot enough to warrant automatically running the fan at shutdown.

https://mechanics.stackexchange.com/questions/27954/time-delay-relay-and-flyback-diode
 
I used a similar circuit for running my anti-runon valve for 10 seconds at shutdown. I used a programmable timer which can handle up to 5A or can operate a relay for more. The timer has many different modes and there are YouTube videos explaining the programming which is pretty easy.
AntiRunonWiring.jpg
screenshot.1436.jpg
 
Hi Steve
I also have the pusher fan installed on my AH with the switch for heavy traffic situation -I solved the problem to cool at the run ending with a thermostat
that works in in parallel to the switch, it works also if I forget the use of the push fan when needed or if overheat occur
https://photos.app.goo.gl/n7hBFmqRAoQd4nST8
 
Hi steve,
Which model Kemo switch did you buy there seems to be more than one on ebay. I have a manually operated pusher fan and I left it on one time when I put the car in the garage and nearly drained the battery. Seems like I need one too!
AJ
 
Hi
I bought a Kemo M113A time switch and two T113A Miniature push buttons from Reichelt electronic in Germany.
cheers
Steve
 

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Steve
so you use this timer/relay to turn on another relay the fan circuit is on?

Also if you have the timer set for say 3 minutes, do you have to push the on button every three minutes?
 
If the concern is for the fan's being left on and running down the batt why not simply power it via circuit that only goes hot when the ignition is on with a SPST between it and the appliance? This gives the option of having the fan come on--or not--automatically and there is no risk of running down the batt as even a Lucas 30 amp generator can cover its demand. If you want to have the fan operate after shutdown for a period of time and then shut down I'd suggest a thermostatically controlled switch rather than a timer but if you want the best of all possible worlds you have both in series.

I have my aux fan wired to the "always hot" fuse block--it is noisy enough so that I cannot leave it on inadvertently and there is less wiring and relays with which to be concerned. Though I am not too concerned with water temp when the engine is not running I do have the option of letting it run.
 
Hi All,

I am a little confused in why a thermostatic actuation switch would not be better. You can always add an on/off switch if it is your desire to control the operation at times and also a timer if long term run-on is a concern. However, if you are going to take advantantage of having a pusher fan, why not really take advantage and let it do its thing when it is needed and eliminate having it on your mind.

Also, as I have experienced when trying out a pusher fan, placing it in the common position in front of the radiator behind the grill creates a block in the path of the airstreem from grill through radiator. Although this block does not seem to create an adverse temperature problem at driving speed, it can cause the electric pusher fan to be needed at a slow running speed when normal air flow would be sufficient to cool the engine and would require the pusher fan be active more often then needed without it acting as a block.

I have mentioned my use of (2) forward low mounted AC auxiliary fans aimed upward at the radiator in my TR7 (without AC) that are the only cooling fans. I find this mounting to be very effective as the forward upward angle of the air stream intersects at an advantageous angle with the cooling fins of the radiator and allow an unblocked air flow from grill through radiator. The fans are thermostatic controlled (no thought on my part whether to use or not) and are also controlled by the thermostat or a timer (which ever hits its limit first) when the ignition is turned off. Although I have also installed an on/off switch as a safety precaution to deactivate the fans manually, it has never been used in over 10 years in use.

Sorry if I am being redundant or missing something others are not,
Ray(64BJ8P1)
 
If someone in a cool climate (UK) feels the need of an auxiliary fan on their Healey, IMO they should first make sure their cooling system is optimum: Modern radiator core with 4 rows, overhaul it if older; backflush the block to remove silt; Texas kooler or 6-blade SS fan. Friends have installed oil coolers and report 5 - 10 degree temp reduction.

Ensure the accuracy of your temp gauge by measuring coolant temp at thermostat housing adjacent to temp bulb. I did that and found my gauge read 25 degrees high.

The TR7/Cobra setup of tilted fans blowing up at an angle is intriguing, but not sure how it would be implemented without cutting a new grille opening below the bumper.

IMO, Dougie's puller electric fan with shroud represents the ultimate electric fan solution.
 
Steve,

Using a standard electric pusher fan would be difficult to mount low but keep in mind that the fan would be used in concert with a puller fan and should only be needed when the car was in traffic and not moving very fast. In this case, pulling air from below the shroud or through the grill would be very doable and should be sufficient to satisfy the air movement requirements of the fan. Also, below aiming upward toward the fan is one way but installing on the side would also work and be out of the direct air stream as well.

If I needed electrical fans to keep my Healey's heat under control, I would choose (2) smaller fans as used in most cars to support supplemental cooling for air conditioning. These would be easier to mount and keep out of the direct air stream and providing substantial cooling air movement during the times of slow or no movement (i.e. traffic on a hot day).

Prior to eliminating engine mounted or relying on the Air Conditioning fans on my TR7, I eliminated the engine-mounted fan and installed an electric pull fan (with shroud) and found it quite good. However, the Healey has little space to incorporate a puller electric fan and this unit was no exception.

Ray(64BJ8P1)
 
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