Dual thermos

[Parksy]

You guys are very helpful. Thanks very much!

[megatexture]

Yes I've got the same, just went out and pulled mine apart as I couldn't remember.............

No silastic used, the probe has an olive ring around it which sits inside a brass connection, the brass connection is screwed into a plastic pipe using plumping tape, the plastic pipe between the 2 radiator hoses is just done up with clamps

Attachment 52417 Attachment 52416

Nothing I do is coshure *L*

Looks good there mate. What diamiter hose is that? I don't think that would fit a zd30crd so check yours parksy, I'm not sure what you have under the hood tb42?

[NissanGQ4.2]

You guys are very helpful. Thanks very much!

Nothing better 2 do at 6am ................and your welcome

Yours is a TB4.2?????? sure i read it somewhere

[Parksy]

Yes mine is a tb42. Don't have any heating issues, I only want extra power and improved fuel economy.

Anyway, I like the idea of using the existing ac fan wiring for the thermos, but mine doesn't work. If I bridge the wires where the sensor on the radiator is, it works though. But at operating temp, the thermo sensors resistance is open. Is this right? Or does it need to reach it's set temp to close the circuit?
The actual sensor thread is 16mm in dia and I've seen different temp sensors on eBay, which sensor should I pick? I've measured the temps on both sides of the radiator and the outlet side is about 20degrees C cooler. The lowest temp sensor I've seen is 75-80c, I may try this first and if I find the fans are constantly running, can try the next step up. I just hope it does run due to the outlet side on the radiator being a lot cooler.

I hope this makes sense.

[the evil twin]

Yes, it is a thermo switch so should be open until the set point is reached.
If the fan runs when you bridge the thermo it means it is either shagged (bad) or the coolant isn't hot enough (good).

If the coolant isn't getting that hot it means the engine is "riding the thermostat" IE the thermostat is only partially open and still restricting flow to keep the engine in the operating range and stop it cooling off.

There is no point running the fans if the radiator is efficient enough in exchanging heat without the need for extra air flow and the thermostat doesn't need all the available coolant flow.
You will defeat the purpose of your fitment IE electrical fans still draw power and use fuel to run them so running them for no reason is counter productive.

If your fan clutch is in good condition the engine driven fan uses very little power anyway so changing to elec won't make a terrible lot of difference anyhow.
The engine driven fan only starts to use noticeable fuel and power when the fan clutch locks up.

[Yendor]

Yes mine is a tb42. Don't have any heating issues, I only want extra power and improved fuel economy.

Anyway, I like the idea of using the existing ac fan wiring for the thermos, but mine doesn't work. If I bridge the wires where the sensor on the radiator is, it works though. But at operating temp, the thermo sensors resistance is open. Is this right? Or does it need to reach it's set temp to close the circuit?
The actual sensor thread is 16mm in dia and I've seen different temp sensors on eBay, which sensor should I pick? I've measured the temps on both sides of the radiator and the outlet side is about 20degrees C cooler. The lowest temp sensor I've seen is 75-80c, I may try this first and if I find the fans are constantly running, can try the next step up. I just hope it does run due to the outlet side on the radiator being a lot cooler.

I hope this makes sense.

Does your receiver dryer for the A/C have 4 wires connected to it or only 2 wires?

If it has 4 wires, this is the main switch to turn on/off the condenser fan. It will have the same 2 colour wires at the receiver dryer as the sensor in the radiator.

The condenser fan comes on when the pressure inside the A/C system rises.

The sensor in the radiator will also switch on the condenser fan once the radiator temperature reaches a certain temperature. Sorry I don't know what this is but I'm guessing it's high.

[the evil twin]

What Rodney said (as usual) ^^^^

There are a variety of configs for the TB42EFI manual and auto and not all of them are in the manual.

It has been ages since I sold mine so cannot physically check but IIRC the Condensor Fan temp switch is towards the top of the Rad.
If you disconnect the plug and test the sensor it will be open cct when cold
If you short the plug the Condensor Fan will run.
I am reasonably confident the switch setting is 97 degrees because the standard Aussie thermostat is fully open at 95 degrees
Because there are 2 other thermostat settings available there may well be 2 other sensors as well

The A/C cutout switch is towards the bottom of Rad
If you disconnect the plug the sensor should test short circuit
If you short circuit the plug the A/C should be OK
If you open circuit the plug the A/C should drop out
The A/C cutout is set for 107 degrees and should close again at 102 on all models from memory

This should translate to the following
A/C off and Coolant below 97 - Fan off
A/C off and Coolant above 97 - Fan on
A/C on and Coolant below 107 - Fan on and A/C works
A/C on and Coolant above 107 - Fan on but no A/C operation
when/if Coolant drops below 103 - Fan stays on and A/C comes back on

Been wrong before and will be wrong many more times but that is my hazy recollection of the system

[Parksy]

You guys are bloody awesome. Very useful information. My drier switch only has 2 wires and the condensor fan doesn't switch on when the ac is switched on. I also replaced the thermo sensor for a 75c-80c one and it still doesn't turn on at operating temp, which I'm not complaining about. Maybe it gets hotter when the temp is warmer, time will tell.

What is the reason for the condensor fan not turning on when the ac is switched on?

[Crate]

If the radiator is not hot enough there is no need for the fan to turn on, even if the ac is on, hence the switch! That switch sounds like it has a very low activation temp? Coolant operating temp should be approx 90 degrees, i believe the thermostat is fully open at 95 deg.

What I think will work for you is to firstly check what the range is of the current temp switch, this should be marked on it (something like 87-92) this means it will close the circuit (Fan on) when it gets to 92 degrees and then open again when it gets to 87 degrees (fan off). Alternatively a thermometer and a saucepan of water works :-).

To wire it up take a ignition feed from the wiper motor, run it to the positive side of the temp switch and wire it in along with the current AC wire.
Then run a wire from the other side of the temp switch to two relays (split the wire into two, and put it to pin 85 in a standard normally open relay)
Then run a wire from pin 86 on the relay to ground, what this will do is when the ignition is on and the temp switch goes above the activation temp (92 deg?) the switch closes the circuit and the relays will activate.

Now just run some power from the battery (fused) through each relay (one per thermo) and to the thermos. Ground the thermos and you are all set up :-)

This is what I have been running for some years now with twin falcon thermo's in my GQ with a tb42 radiator and injected 304 V8. With the exception of keeping the AC circuit, but that shouldn't be a problem.


PS I am running one of these, TFS123 perhaps? (on @ 92 deg and off @ 87 deg)

http://www.tridon.com.au/Products/Pr...5&G=483&P=2014