Electric Fan clutch

[ak diesel driver]

pretty much the plan as I don't want the clutch engaged all the time the AC is on

 

[WarWagon]

Gotcha.

Given it acts like a regular 'ole viscous clutch, I'd just hook the controller's Override node to a switch and leave the A/C circuit out of the equation given this is closer to how the OE thermal clutch works anyway. Also, (as noted) can still manually engage the clutch while sitting still to give the A/C a boost without eating much extra fuel.

The entire point of this is to improve the lacking OE design. With R134A the lacking OE design has to use a high side cut out switch when the condenser overheats. Fail the switch and watch the high side safety valve vent freon or any weak seals or parts... We are talking fuel sucking 300PSI+ head pressures before the switch trips. This is hot enough to bring on a 180 degree spring thermal fan alone.

The minimum fan speed when unlocked is not enough airflow to keep R134A working well. So if you are going this far with a clutch design change IMO you may as well include an AC trigger.

The difference between a worn out fan clutch sort of spinning the fan and a new clutch is ice cold AC vs. just cool. And this is on a 2002 rear air Burb I just worked on this past weekend.

The fan doesn't run all the time with AC use - just when needed. And IF the fan runs more than you like due to AC use add a small electric fan to the condenser that comes on with the compressor clutch. Not using a fan when needed is just stressing the compressor and sucking fuel with excessive head pressures and temperatures while it attempts to work.

 

[ak diesel driver]

If I lived in the south that would probably be what I would do. Up here I only run the AC a fraction of the time you guys do, mostly because I don't care for the wind noise from windows being rolled down. With the override switch I can still turn it on when needed.

 

[THEFERMANATOR]

you could always tap into the high side reirc switch mounted at the condenser. it closes around 300 or so to switch the ac back to inside air to help bring pressures down. or like in the article for the ford with a horton clutch, you might be able to use a taurus dual purpose cutout fan switch.

 

[spollock818]

I'm sitting here in front of my screen with popcorn waiting to hear how this all plays out. I would love to hear how this combination plays out when towing. Seems like 60% could be great for day to day driving in hot climates and grades unloaded. Then when towing, just override and instant cooling!!

 

[WarWagon]

I'm sitting here in front of my screen with popcorn waiting to hear how this all plays out. I would love to hear how this combination plays out when towing. Seems like 60% could be great for day to day driving in hot climates and grades unloaded. Then when towing, just override and instant cooling!!

Auto control for the fan is the only way to go. Other than downshift for cooling if I notice a ECT spike I have way too much to do when towing than to be staring at the ECT gauge and manually overriding a fan all the time.

 

[ak diesel driver]

Sensor installed in passenger side head. Easiest to remove inner fender IMO

 

[ak diesel driver]

Forgot the pic LOL

 

[JayTheCPA]

Thought of a limited and secondary effect of this mod. Ignoring TCC effects, manual engagement can help with braking.

 

[spollock818]

Any update?

 

[ak diesel driver]

No been super busy since the fire we had. Just finished up a big community service clean up project yesterday. Have my old truck to drive still so I'm not in a rush to get it done. Sorry if your waiting.

 

[ak diesel driver]

Pretty much have it installed. The derale controller switches the ground so it made me think a little more than usual.

 

[JayTheCPA]

Is that fan from the 7.3 diesel, or the gasser?

 

[ak diesel driver]

Gasser

 

[WarWagon]

I caution you that the gasser fan may not have enough blade pitch to keep you cool when needed. Already failed an experiment towing with a Trailblazer SS fan (395 HP 400 Lb Ft Corvette gas engine) bolted on the 1993. Yes, even in cold weather you have to keep the engine cool when working hard, granted, you can get away with a little less fan when you are under 100 degrees and no AC...

You could find way lower head pressures running R290 in states that allow it vs. the Garbage R134a the R12 Scam forced on us. You get R-12 outlet duct cold performance with say Enviro-Safe™ Industrial R134a Replacement Refrigerant - Flammable to an open flame or spark and proceed with caution if used in systems designed for non-flammable refrigerants.

The R4 compressor needs all the help it can get and even some modern systems can work better with it.

R1234yf is the supposed replacement for R134A and it's flammable... So what's the problem again?

 

[ak diesel driver]

the fan clutch on my 96 never did work so it'll have to be better than that. I am keeping my eyes peeled for a better fan

 

[ak diesel driver]

so before I buy a new fan clutch, I think the used one I bought is bad, I thought I'd see if any of you tron guys have any ideas if I'm wiring this wrong.

 

[ak diesel driver]

according to the guys on the ford forums you ground the blue wire to get full engagement

 

[schiker]

Can you attach a bigger scan or picture? Or describe how I might can zoom in.

Also what are you experiencing? Does a clean 12V and ground cause max lock up? Can you measure any resistance across the solenoid or current draw while on?

 

[ak diesel driver]

I'm experiencing nothing! My controller switches the ground, there's a wire for fan control to/from the PCM. Another for power. Another for voltage reference and another for speed signal