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Contact the Auto Cool Guy: 562-367-3225 autocoolguy@yahoo.com
Please AVOID ENDLESS EMAILS, TEXT AND VOICE MAIL
The On Line Store Page 1 below. . . .
READ THIS - HOW WE CONTROL TEMP!
The Auto Cool Guy has a better way to control engine temperature.
We use Pulse Width Modulation of your fan to control its RPM. Our sensor monitors the radiator outflow temp and adjusts the fan RPM to keep the outflow at a constant 15 to 20 degrees BELOW the thermostat temp. This way, the thermostat can regulate engine temperature. Use a laser temp gun and put the red dot on the outflow area and on a black dull surface for good results as you adjust the BLACK knob. Avoid shinny chrome surface due to temp errors. Take your time and do not rush this setting. After you have made this adjustment, you should see ROCK SOLID engine temperature. You will notice speed and motor load will effect your fan RPM - see its working.
By the way, fans with Auto Cool controllers do not KICK ON and off, leave that to the brand X controllers. Please don't tell me your Auto Cool wont KICK on.
FEATURES AND CONTROLS:
Soft Start limits inrush current with pulse width when the controller is powered up. Inrush current is a brand X controller killer when starting a fan motor from a dead stop.
A/C FAN SPEED control has a small pot on the side of the controller. When 12 volts is applied to the A/C controller pin, use a small flat blade screw driver to set this fan speed. The radiator temperature control mode will over ride the A/C fan speed automatically. If not used not a problem.
FAIL SAFE: The fail safe mode turns the fan on full RPM. The FS mode is turned on by grounding the FS pin. Use a small switch from FS to ground. You can turn FS mode on or off any time.
COOL DOWN TIMER: When you turn off the IGNIITION, the fan will keep running for a period of time to cool down your radiator and then shuts down.
FAN BUZZ: The buzz is caused by the fan blade and the armature shaft not tight.
We have found the Mark VIII fan have been reported at no buzz fans.
Our HF-125 controller runs at 7Khz to prevent the buzz but may have a high frequency tone cured by a large filter cap you see below. If your fan is brushless, use our HF controller only. The fan will vibrate at low RPM with low frequency controllers.
START ENGINE: As the motor and radiator is getting warm to hot, the fan will start turning slowly and gain RPM as the temp rises. The RPM will hold at the point of regulation set by the black knob.
OUR NEW HF-150 CONTROLLER WITH FRONT PANEL ON/OFF SWITCH - MORE POWER AT HIGH FREQUENCY SWITCHING WITH EIGHT POWER TRANSISTORS & BIG HEAT SINK! HAS SOFT START, FAIL SAFE AND A/C FAN SPEED CONTROL! USE ON BRUSHLESS OR BRUSH TYPE FANS. BASE 5 X 7 INCHES.

Darryl,
I just wanted to let you know that the HF-125 I ordered from you this summer has been absolutely great. As I said, I haul a lot, and big trailers, with my Powerstroke, and now that I'm running your controller, I'm finally getting the benefits of converting it to electric fans. All these years hauling trailers and I've been religious watching temps - I still am, but I can tell you it doesn't matter now if it is 40*f or 100*f, loaded, unloaded, headwind, no wind, 50mph or 80mph, the temperatures are stable all the time. I could not be happier with your controller. In fact, I'm so happy I just ordered a second one for one of my other trucks that I'm converting to electric fans now that I have found the proper way to control them.
Thank you so much for making a quality product.
Joanna Byrne
Lubbock, Texaseasy.


ATTENTION AUTO COOL SHOPPERS:
THE STANDARD BRASS SENSOR IS SOLD WITH ANY CONTROLLER AT NO EXTRA COST. NOT INCLUDED IF YOU PURCHASE ANYOTHER SENSOR. WITH A CONTROLLER.
WE ALSO LOWERED THE PRICE ON THE AUTO COOL 200 LOW FRQUENCY CONTROLLER. ANY QUESTIONS, GIVE US A CALL!
Auto Cool Quality
A lot of Auto Cool buyer's ask me why the our controller last for years when other controllers have early failures. This may be because of the large heat sink and over rated transistors on Auto Cool controllers. This keeps the internal heat to a minimum and avoids burning up transistors. Also, relays are not used in switching fan current.
The Auto Cool controllers are big but its for a reason - its to absorb heat generated from switching fans with Pulse Width Modulation. The Auto Cool controllers are made from 1/8 inch aluminum base plate for a robust heat sink. Heat can distroy a transistor with thermal runaway if not controlled with a good heat sink.
Soft Start is used on all our controllers. Its works when the controllers start a fan motor from a dead stop.
The pulse width starts from very narrow and widens to give your fan motors a Soft Start. This avoids huge
in-rush current that could even blow the diodes in your alternator! If you intend to purchase the brand X controller for a lower price, see if it has soft start and relays that could fail over time!
There is no calibration or set up required, just install the controller system and drive.
The printed circuit boards inside our controllers are coated with a clear coating to protect the electronic circuits from moisture and FOD. The design of the Auto Cool controllers are so that water will not be held internally.
The Auto Cool Guy found a real Russian Radiator fan controller!




Photo on the left is a new Russian controller. The three other photos are the results of high fan pulse current burning out the PC board and blowing the transistors.
We received an email from Dmitriy in Kazakhstan. He was having problems with his Russian made radiator fan controller. He was also having difficulty with the complex programing of this controller.
Notice that this Russian controller used two small TO-220 transistors and it looks as if they are glued down to the top cover. According to this manufacturer, this controller is rated at 420 watts. Sounds like a good high number, right? That's only 30 amps at 14 volts!
He made the right choice and purchased the NB-100 Auto Cool controller to replace this Russian controller.


Auto Cool Controllers use large solid state transistor to switch the DC fan motors with Pulse Width Modulation. Transistors never arc like relays so solid state means reliability and a long life.
This "controller" is being sold on Ebay and on the web. They are actually AC electric hot water heater controllers being sold for automotive use. Note the very long probe and the metal tube that could break to leave you without a working fan controller. You may find one of these in a black plastic case. The long probe could cause leaks in your radiator over time.
Hot water heater controllers
sold for automotive use???

This is a YOUTUBE video on a Derale PWM fan controller that had problems and was sent back to the vendor. The Auto Cool Guy gets
a lot of calls and emails on the Derale controllers failures!
Notice that the Derale contollers have PVC wire extruding out of their chassis. However the Auto Cool controllers have terminals and brass studs for high current connections.


You can avoid this type of cooling system break down by keeping your radiator temperature constant with the Auto Cool controller. If your car has a controller that cycles on and off, this can cause pressure and temperature peaks that could lead to cooling system failures and you stranded on the highway!
We received an old Spal controller from Bill and a his email explaining the problems he encountered with the Spal and other PWM controllers.
All of the other PWM controllers he purchased failed, with very poor or
no customer service!
Read Bill's letter in the PDF below!

Milton has been receiving a lot of reports on Flex-A-Lite and Derale PWM controllers that are failing. Customer service is another problem with these Brand X controllers that are not made in the United States.
The Auto Cool Guy has a proven track record of quality, long life and # one in customer service! Go to the "Email" page on this web site and see what Auto Cool customers are saying about the Auto Cool Controllers.