Add an electric fan to A/C condensor 2005 Ram 3500

[rashwor]

Ladies and Gentlemen,

I am looking to add an electric fan in front of my A/C condenser to help with cooling. I have seen where some have done this and said it helped. I want to try it.

With that being said, I have a fan (BeCool 16" pusher). I need help with the wiring. I am not and do not claim to be an electrician, let alone an automotive electrician. I have searched threads on here and sadly, they are over my elementary electric comprehension brain.

My thoughts for how I would like it to work are 1 of 2 ways. First way: Trip a relay to power the fan when the A/C compressor kicks on. This seems optimum as it is only running when I need it to run. Second way, Trip a relay from a fuse that gets power when the ignition is in the run position.

If you have done this and can help with instructions (part number and how-to) on wiring this up, I would greatly appreciate it. Thanks in advance.

 

[Killer223]

i have no part numbers, but relays are easy to get and the wiring diagram is usually printed on them.
That said i'd get a thermostatically controlled fan. so when the condenser get to X temp the fan kicks on. or yes there is or should be a way to pull the signal form the ECM as to when teh compressor kicks on the fan does as well. you'll need the service manual for your truck.

next i've seen 100's of times the fans that mount to the front often times wear holes in the item mounted to.
make sure the cooling system fan is working correctly, the clutches do wear out in them. if you have the option, you can always kick into high idle when not moving.

 

[Tuesdak]

When does it need extra cooling from the electric fan - for you? The electric fan is a restriction to our massive mechanical driven fan and is only useful at idle IF the clutch fan isn't kicked in.

Yes, quick and dirty wire it off a relay from the compressor coil. Condenser temp probe would reduce the "windmilling" restriction because the AC doesn't use the fan a lot over 45 MPH unless the blower is on high and it's over 100 out. You will need a probe that works around 150 degrees F - most are calibrated for radiators and don't kick in low enough to do the AC any good.

X2 on the high idle.

How does the condenser look? Lots of bugs or bent fins make a difference.

Heater core bypass is another AC performance option.

Evac and recharge the system as these systems like to pop the relief valve and vent refrigerant at idle now and then. Low charge doesn't cool as well.

Coat a new condenser with a thermal dispersant for 1/3 better efficiency. (Aka professional shop that does coatings.) Same with coating the evaporator as well.

Alternate hydrocarbon refrigerant is worth looking into. (It works way better than R134a vs. risk.)

 

[rashwor]

Thanks for the input. Lots of good ideas that I will address as well. I am moving forward with the fan install.

 

[JKosten]

First, I agree with the posts about blocking air flow to the charge air cooler, radiator and condenser, and that it could damage your condenser depending on how you mount it (please don't use the zip ties that poke through it).

Also I recently replaced my condenser and noticed the system was not able to shed almost 50 degrees of heat across it now. As is ages and becomes less efficient I will not expect that level of performance, but it is something to consider.

But if you are going to install the fan here is a basic wiring diagram for how to set it up safely for the vehicle's existing wiring.

 

[Hoefler]

Install a trinary switch on the high side charge port, wire in the high pressure side of the switch. When the pressure goes up from little air flow across the condensor, the switch will turn on the fan. Whne the pressure drops, it will turn off the fan.

https://www.ebay.com/itm/NEW-OEM-Volvo-Trinary-Switch-VOE11005913-/142702601450



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