On 8/26/12 3:32 PM, micky wrote:
On Sat, 25 Aug 2012 11:34:09 -0400,
wrote:

On Thu, 23 Aug 2012 07:39:01 -0600, Tony
wrote:



micky wrote:
On Wed, 22 Aug 2012 21:28:32 -0600, Tony
wrote:



micky wrote:
On Wed, 22 Aug 2012 15:29:45 -0500, Vic Smith
wrote:

On Wed, 22 Aug 2012 15:26:41 -0400,
wrote:

What do you call this, where do you find it?

I need to buy the kind of thermostat used to turn on a car's radiator
fan (or at least an electric swtich that will close at 120^ F or
higher) , and I also need it to use as a sensor a thin tube (2-4 mm)
that will go into a radiator or heater hose, between the metal housing
and the hose that surrounds it. Am I being clear?


No. Just explain the purpose of the switch and where you want to use
it. Then you'll probably get answers.

In the winter, I don't want the heater fan to go on when the engine is
cold because cold air will come out of the heater**. So I want to put
the sensor in the heater hose and let it turn the fan on when the
coolant is reasonably warm.

**OTOH, if I turn the fan off with the switch on the heater/AC
control, I'll go days without turning the fan on again, until I
finally notice how cold I am.

Hi,
Did not mention how old the car is. Does it have belt driven fan or DC
motor driven one?

2000 Toyota. DC motor for the radiator fan, but the fan I'm trying
to stop is the heater fan. (also a DC motor.)

Hi,
Then there is 'stat controlling the rad fan. You need separate one?
How about using one already there.

Probably.

I mean: Proably I need a separate one.

I don't want to wait until the water is hot enough to turn
on the radiator fan. It's warm enough to heat the passenger
compartment quite a bit before then.

Plus the 12v might come from different places., and not just from the
battery, for the two fans. I'll look into that.

I've looked at the wiring diagrams 3 or 4 times, but never before for
this purpose.

So I looked again and the radiator fan is powered through the engine
main relay and the fan no.1 relay, and then goes to ground. Its
thermostat connects to the fan no. 3 relay and is in the midst of a
jumble of wires

The heater fan gets power directly from the through the heater relay
(one side of which IS connected to the battery) but tts ground wire
doesn't go straight to ground. It goes to the "AC blower motor
linear controller", and the diagram doesnt' show what's in that.

So I don't know how to use the same thermostat, and I'd be afraid to
try. I suspect it can't be done.

You need to wire the new switch in series somewhere between the
Battery and the "Controller". It will act like another "Heater relay"

Now, as you describe =

Batt----Fan------------------HtrRelay----Controller---Ground

After=

Batt----Fan----NewSwitch-----HtrRelay----Controller---Ground

New switch could also go between Batt and Fan if easier to wire; or
between HtrRelay and Controller

This way both the NewSw and HtrRelay must be closed for fan to run