Wiring For Thermos

[Sarumatix]

Yeah I bought an EL thermo fan for my car and am wondering what the best approach to wiring is?

[Cubes]

The EL's run 2 plugs from memory, ef's run the 1 plug.

You can either wiring them up parallel so they run flat stick when enabled or you can run them as a 2 stage. Being low/high.

Wire them in series for low, parallel for high.

2 stage will obviously require 2 temp sensors. Davis Craig make one, I believe jaycar also have a nice little kit.

Might also be worth chopping off the old plugs if you can't find anything similiar and grabbing a set of new plugs from the local auto shop for $3.95, much nicer than using bullets or similiar.

You 'may' require a little fibreglass kit to touch up any small bits you have to cut.

[Sarumatix]

Can't I just use the stock temp sensor?

[Cubes]

Yes you can.

BUT how are you going to trigger the thermo's. The stock temp sensor reports a voltage that corresponds to a temperature.

[Sarumatix]

Yes you can.

BUT how are you going to trigger the thermo's. The stock temp sensor reports a voltage that corresponds to a temperature.

hmm well i'm confused about this, I know there are 2 thermostats, one on the intake to the engine and the other at the bottom of the radiator. I have an aftermarket radiator which further complicates things, however I thought the thermostat at the bottom of the radiator was just a temp switch that was triggered at around 86 degrees (or 82 depending on which thermostat you use). I was just planning on running a relay off this to switch the fans. After closer inspection I noticed a relay in the fuse box in the engine bay called "rad fan" and a fuse there as well. I was hoping I could some how use this. I don't really want to wire up another thermostat and leave the current one in if it does nothing.

[blind_elk]

hmm well i'm confused about this, I know there are 2 thermostats, one on the intake to the engine and the other at the bottom of the radiator. I have an aftermarket radiator which further complicates things, however I thought the thermostat at the bottom of the radiator was just a temp switch that was triggered at around 86 degrees (or 82 depending on which thermostat you use). I was just planning on running a relay off this to switch the fans. After closer inspection I noticed a relay in the fuse box in the engine bay called "rad fan" and a fuse there as well. I was hoping I could some how use this. I don't really want to wire up another thermostat and leave the current one in if it does nothing.

The one in the bottom tank of the radiator is a simple thermal switch. It switches a relay that activates the A/C fan.

If you hook into the switched output of that relay (on a 32, it's 2nd from the back, I think), and use that to switch a relay that powers your thermo fans.

[Cubes]

Sarumatix,

The thermal switch in the bottom rad tank enables around 94degree's.

Providing you can track down another at a lower temp use that.

Researching in to these temp switches a 'little' I've found they don't exactly turn on over say 87degree's then turn off once temp is below 87, they tend to turn on at say 87degree's than it takes until maybe 83degree's. Temps used are an example.

So not really what we want.

[Sarumatix]

Isn't that exactly what I want? But yeah the intial temp that it turns on would be important. Come on I know some of you guys have actually wired these things up.. what are the options here .

By the way, EL falcon thermos blow *&^*&^ing shitloads of air lol.

[boot_it]

Sarumatix,

The thermal switch in the bottom rad tank enables around 94degree's.

Providing you can track down another at a lower temp use that.

Researching in to these temp switches a 'little' I've found they don't exactly turn on over say 87degree's then turn off once temp is below 87, they tend to turn on at say 87degree's than it takes until maybe 83degree's. Temps used are an example.

So not really what we want.

i do rb conversions into silvias and ive never had a problem using this switch to turn on and off twin thermo fans and all the cars i have done have never got hot

[Cubes]

My RB20 and Rb30 often hit 90 odd degree's.

The std temp guage reads half from ~70degree's right up until 109degree's.

What temps have these silvia's been running at?

I'm assuming you've taken note of what engine temp the switch activates the thermo's?

Have you fitted a lower temp thermal switch?

[BH_SLO32]

Gents,

One option attached as requested. I have shown a relay with dual switches to suit 2 thermos with individual plugs although there is no reason why you can't use a relay with a single switch provided the relay and associated wiring is rated for the current draw of the 2 thermos.

The arrangement is such that thermos will be operated by the temperature switch in the bottom of the radiator although I do recommend installing an additional toggle switch in the car in case the temp switch ever fails. The arrangement of the existing thermo fan for the radiator is a reflection of the wiring found on R32 skylines so keep this mind when looking at the diagram. The fusable link (F/L) and relay for the factory thermo (referred to as radiator fan on diagram) can be found in the fuse/relay block near the battery for R32 skylines.

EDIT: This arrangement works fine for the GTST but I cannot confirm for GTRs as the ECU earths the temperature switch under conditions I am not privy to this point in time.

I also recommend purchasing another temperature switch from someone like Autobahn which will switch on at around 87 degs and switch off at around 83 degrees as an example. The standard temperature switch as Cubes pointed out, typically switches on over 90 degrees (97 on my R32). The temp switch I purchased for my Bro-in-law cost around $40 from memory.

Remember, the thermostats on the RB motors typically open at around 76-77 degrees so you should retain some margin over this when selecting the operating range for the temperature switch.

Hope this helps

Cheers

DualThermoWiringR32.pdf

Edited March 15, 2006 by BH_SLO32

[Sarumatix]

yeee haw that's what I was after, that's exactly the wiring diagram I had come up with on a piece of paper but decided it might be dangerous based on the stock thermo. I will get a new thermostat, what am I asking for and from where? I presume repco or autobahn?

[Sarumatix]

Wow ok well I went ahead and wired it up basically along the same lines as what BH_ posted and it worked to some extent. However it seems that when the rad fan circuit is engaged the clutch on the aircon pump does something fancy (I presume it disengages aircon which makes sense given that this circuit is designed as an overheat circuit and the last thing you want when a car is overheating is the aircon). So unless i've missed something here there is no option but to add a new thermostat circuit or remove the overheat circuit and rewire it to my own nefarious purposes. Incidently using a kettle the thermostat switches on around 88+ degrees and stays on for around 3 minutes (although i'm pretty sure this isn't a stock thermostat).

Cubes: I assume the circuit you are talking about from jaycar is this: http://www.jaycar.com.au/productView.asp?I...eMax=&SUBCATID=

Edited March 15, 2006 by Sarumatix

[Cubes]

Sarumatix,

Do remember that 88degree's will be in the lower bottom tank.

The bottom of the rad is cooler than the top.

For one the water leaving the motor enters the radiator from the top and two the top is always hotter. So you will find 88degree's in the bottom tank will be reading ~94 or more in the top tank.

It is strange that your a/c disengages when the switch is enabled.

Mine doesn't.

Possibly there isn't enough air flow cooling the condensor (remember the clutch fan is normally working) as a result the a/c gas cannot be cooled resulting in the compressor being turned off.

Do you still have the a/c condensor overheat fan connected? Have your wired it up so that it comes on as soon as you hit the a/c button?

This is the way it should be for australian conditions.

That wasn't the fan controller I was thinnking of but it will work and is cheap, it 'may' even work if you were to hook up the stock temp sensor.

To know for sure you will have to find out the voltage output of the sensor supplied and fingers crossed it will be similiar to the stock nissan temp sensor.

[BH_SLO32]

Sarumatix,

The wiring for the GTR and is slightly different to the GTSts in that the temperature switch is not directly earthed but connects to pin 6 on the ECU where it is then earthed. I assume the ECU earths it straight away but am not sure. I figure the ECU probably only turns off the thermos when accelerating as per the AC control.

The operation of the factory thermo on the 32 GTSTs is completely independent of the AC operation. It simply aids the factory clutch fan when temps rise. Having said that the fan is likely to turn on when the AC is switched on thanks to the extra load of the compressor.

Given you have a GTR motor in your GTSt is it possible the temperature switch earth wire has been connected to pin 6 on the GTR ECU (assuming you are running the GTR ECU)? Does your AC work with and without the thermos? It should.

Cheers

Edited March 15, 2006 by BH_SLO32

[Sarumatix]

well I just used the thermostat under the radiator switching a relay. It works fine and with the EL falcon fan quickly cools the radiator, and the fans are off again in about 3 seconds. I want to add a bit of hysterisus so i'm going to add a 1 minute timer to it, and I might invest in a lower temp thermostat. Anyway as a temporary measure it worked fine and my car is now running perfectly again. The difference in performance is only slightly noticeable but hardly worth getting excited about .

[Cubes]

Take note of any fuel economy improvement and report back.

Care to share any pics?

What I plan to do is use the std lower rad temp switch as the high speed setting for the thermo's, 94degree's is a little high though hrmmm.. I'll most likely drop a slightly cooler one in say 90degree's, really depends whats available.

I'll then possibly use the jaycar setup as the low trigger.

[Sarumatix]

I'll put some pictures up as soon as I can get my grubby mitts on a digital camera. Fuel economy hasn't been noticed because my car is back on the road after 3 months (fuel seems to be vanishing ). I have definately noticed an improvement in throttle response (already have lightened flywheel) with rev's picking up even faster and dropping off faster.