Recommended control switch for electric fan on SPL

[jhayden]

Received a nice PM from an SPL owner asking my recommendation on thermal switch for an electric fan conversion. Honestly, it’s been so many years ago that I made the switch on our SRL that I can only offer my experience with (whatever) brand I chose at the time:

After reading some reviews regarding the sensing accuracy of several options, chose the type that has a sensor which slides into the upper radiator hose. The sensor is attached to a wire about the thickness of baling wire, so initially there was a problem of getting the Nissan braided hose to seal around the upper radiator neck (unless the clamp was tightened more than I preferred). Replacing the braided hose with a conventional one from Gates took care of that – zero drops. Of course I saved the braided one, along with the 4-blade fan and shroud if a new owner prefers to return to that.

That was quite a few years ago, and the adjustable sensor and Spal fan have given zero problems. I do have a back-up manual switch which I use sometimes to verify that it would work if the adjustable switch fails to come on at the selected temp. I also experimented with the rheostat to check for adjustability, making it come on a bit earlier in summer driving than in winter, and it’s always worked without a hitch.

So, what’s new on the market that works for the SPL? Happy with our current setup for several years now, I simply haven’t kept up with new products out there, so I answered his PM by saying that I would put his question to other owners who may have made the switch more recently. Too, I have no experience with SPL plumbing, and his has the two bolt tower.

Your feedback will be appreciated!
Jon

[Daryl Smith]

Before I went EFI and computer control I was considering a switch similar to this:
https://www.summitracing.com/int/parts/ ... /overview/

I would drill and tap a hole in the head near and below, but careful not to interfere with, the thermostat, and tap the hole for the sensor/switch. I beleive there are 1 and 2 wire versions. Use in conjunction with a relay.

[Nissanman]

I used an industrial temperature switch designed for dishwashers and washing machines etc[KSD301].
They are available in a variety of temperatures and either NO[Normally Open] or NC[Normally Closed].
For your cooling fan you need a NO switch with an operating temperature of say 85DegC.


THERMAL SWITCH 85 DEG NORMALLY OPEN 250V 10A RATED MOUNTING : 24mm FIXING CENTRES OPERATING TOLERANCE : +/-5deg C RESET TEMPERATURE : 10deg C MINIMUM BELOW OPERATING TEMPERATURE
https://www.ebay.com.au/itm/5pcs-Thermo ... ctupt=true












The sensor is mounted immediately opposite the thermostat outlet hose on the radiator core.
No relay is required since the switches are rated at 250V and 10A, more than enough for a 12V cooling fan.
This method avoids interfering with hoses to immerse a temperature probe or drilling/tapping for a threaded sensor.