Adding fan

[Randomrunner12]

Hey yall,

going to be adding an AC condenser fan to my truck and have a question. Based on the picture, and that I will not be running a thermostat for the fan control, but rather running the fan wiring harness through my auxbeam gang box so I can control when I want to turn fan on, how would you connect the fan wires.

Red wire is fused battery power
White would go to a 30amp CB (is this needed)
Black wire would go to the thermostat (thermostat not being used, run to fan as power wire instead?)
Blue wire becomes ground to fan off relay?

Am I thinking this wrong?

 

[Topzide]

87 isn't a ground, that would go to fan for when relay is energized to turn on. Yes I would use the CB on the white wire(86), easier to reset than replace a fuse if it blows(protects the truck key on power). Just add a switch that would provide a ground when you turn it on(85). This will power the coil to activate the relay to turn on the fan(87). power from battery(30) is correct. 87A would have power all the time when wired this way. This site really helps with relay wiring; https://www.the12volt.com/
The diagram that's provided with the fan is a bit confusing! Hope this helps.

 

[Ozymandias]

Have you ever had the radiator stack out of the vehicle and cleaned them out with a pressure washer?
I had to do it this spring after my fan started to come on at the interstate and 75mph.
The amount of dirt collected in the 5 radiators was impressive so to say.

Nice side effect, the AC was a lot cooler* after the clean.

*idling and low speed

 

[petersonj]

@Randomrunner12, the relay coil (between 85 and 86) only draws about 200 milliamps or less when activated. A 2 amp fuse would be more than adequate. A 30 amp circuit breaker (noted in your diagram) could allow small gauge wiring in the coil circuit to catch fire if a direct short to ground occurred.

- John

 

[Tuesdak]

going to be adding an AC condenser fan to my truck and have a question.

WHY???

The ONLY place an electric fan helps is below 45MPH for the A/C only. Generally parked at idle engine RPM. I have written about others finding the fan helps the A/C not vent refrigerant out of the relief valve. If you want it for A/C performance than have the relay controlled by the compressor clutch 12v.

At speed the fan becomes a restriction form the "windmilling effect". It's why propeller airplanes want the engine stopped completely or the propeller feathered to reduce drag say during an engine failure. Even running at full speed the fan can be a restriction to the main cooling fan esp. at speed, high engine RPM, and full fan clutch lockup.

As above clean the stack and replace the fan clutch if it's over 5 years old. A pressure washer can quickly fold fins over so not my first choice.

In summery if you are having engine heating problems a wimpy electric fart fan strapped to the condenser is NOT the answer.

 

[Ozymandias]

Pressure washer works fine if you know what you do.
I've done it for the last 30 years an several radiators of all kinds.
There have been some that where to weak of a construction but you see that instant if you start from a distance and in a corner. If they fold - stop right there

Not to close and even more important always at straight 180° spray angle.
And always back flush from the rear.

 

[crispyboy]

We have a diy carwash at my work. The pressure isn't too intense like a pressure washer. I use it along with a lot of soap suds to clean the engine bay and radiator from time to time. A lot of bugs can get pushed into the fins. Last month I changed out the original thermostat and flushed the cooling system when I serviced the egr cooler. There wasn't any trouble with cooling but did it out of preventative maintenance. I noticed that the temperature gauge is a bit more steady afterwards. I used an OEM Cummins thermostat from Geno's. I have always been impressed with how good the cooling system works in this truck.