Hotter than Hell in S Tex. - A/C Aux fan install ??!! (1 Viewer)

[Tools R Us]

Let me know spike if you find the perfect fan at napa...I need to do this soooo bad.

Lopers had the Derale 16514 in stock that last time I was there, it's the same size and configuration as the discontinued 'Zone fan.

http://www.derale.com/electricfans.shtml

I had to check my 'Zone fan after -Spike- posting that they are junk, it's tight and runs smooth, Rob's is working on it's second summer, Phil reports that his Derale is still going strong after several summers, so you must have gotten a lemon there buddy?

 

[greauxpete]

Wired it up with a 25 amp fused wire from the battery to a 30 amp relay mounted between the washer bottle and aircleaner duct on the fender well. The relay is turned on by power tapped from the A/C clutch, so the fan runs with the compressor.

Tools R Us,

The way you explain the wiring here - does your fan cycle on and off with the compressor? If so how could I wire it up so that the fan does not cycle with the A/C?

 

[Tools R Us]

Tools R Us,

The way you explain the wiring here - does your fan cycle on and off with the compressor? If so how could I wire it up so that the fan does not cycle with the A/C?

Yes the fan cycles with the compressor, that's when the cooling system is seeing the highest heat load and at this time of year in Arizona, cycle = more on than off.

The relay could be triggered by most any system on the truck, if you wire it to the headlight circuit it will only run when the lights are on! Some thoughts on ways to trigger it in this post.

https://forum.ih8mud.com/showpost.php?p=597024&postcount=50

 

[cartercd]

Disappointed in auxiliary fan mod

I installed the 12" Derale Tornado fan (#16512). Some manufacturers recommend against installing these through the radiator using zip ties on off-road vehicles, so I fabricated brackets and tied into some existing captive nuts. The fan sits about 1.5 inches away from the condenser. I am going to trigger the fan via the A/C pressure switch (see https://forum.ih8mud.com/showthread.php?t=103530&highlight=a/c+pressure+switch), but for now it is on a manual switch.

With the system thoroughly warmed up, windows down, a/c on coldest setting, at idle, and auxiliary fan on, I only see 1-2 degrees difference at the vent compared to when I switch the fan off and let the system reach equilibrium. The difference is imperceptible from a comfort standpoint.

My a/c was recently evacuated and refilled, my condenser and radiator are clean, I converted the fan from "puller" to "pusher" per the instructions. The only things I can think of that might contribute to the minimally beneficial performance is the way I mounted the fan. Since the fan is 1.5 inches from the condenser surface, perhaps air is taking the path of least resistance and not blowing through the fins. Do I need to fab some type of shroud or remount the fan closer?

Any advice would be appreciated.

 

[Tools R Us]

That fan like most electric's is designed to be a contact type. By mounting it way from the surface the efficiency is greatly reduced. The condenser on the 80 is soft mounted on rubber mounts and moves separately from the body, so to contact mount the fan it needs to be mounted to the condenser or it's frame. I agree about not liking the zip pins and have seen problems with them, mostly from coming loose and probably from not being installed tight enough.

A racer buddy of mine showed me the lock it in place with foam tape trick and said that he has never had a problem and has been going it for years, he builds some very nice cars that have done very well in pro offroad.

That install is on brother Rob's truck, it's good to have brothers to try new stuff on! I checked it on our wheeling trip last weekend and it's still rock solid and he's very pleased with its performance with the simple clutch activation after a year of use.

The tricks to a good zip pin installation, put the pins centered between the tubes as much as possible, so even if one becomes slightly loose it's not rubbing on the tube. Use foam or better yet double stick foam tape at all contact points and tighten the pins until the foam is fully crushed. Or make a mount to hold it to the condenser frame. Either way contact fans are a maintenance liability, they need to be checked paretically and if loose repaired before a hole is rubbed in a condenser tube.

 

[citadel]

anyone have pics of using the zips or tape with the install?

 

[-Spike-]

I used some 1/8" thick high-density foam tape on the entire circumference of my fan. I also ditched the zip pins after the first two failed to tighten to my satisfaction. I used zip ties and fabbed some isolation mounts using t-nuts (with the teeth folded back) and double-sided tape to protect the condenser. I used 2 zip ties per mount point, one as a loop around the edge of the condenser and another 'safety' put through the fan mount, condenser, and t-nut with the capture end cut off another zip tie on the back side, similar to the zip pins but IMO more reliable.

The zip pins I got with my Flex-a-Lite fan looked to be superior to the average offering, in that they were threaded like a bolt, the head hex-shaped and slotted so it could be tightened with either a screwdriver or nut driver. However, as mentioned above, they instantly failed. I was very careful with the second one I attempted to install, to no avail- very little tension resulted in it stripping right off. I considered running small bolts through the condenser, but discarded that idea. Perhaps I will try nylon screws on the next install, or if I have problems with mine.

-Spike

 

[Tools R Us]

The Derale pins were very nice, couldn't break them. Bummer about the Flex-a-Lite ones, but that not the first problem that I have had/heard of from their products.

The tape and pins can be seen in the pix on post #48.

https://forum.ih8mud.com/showpost.php?p=596415&postcount=48

We used the plastic ones;

http://www.derale.com/elec-fan-accessories.html

 

[citadel]

may be a dumb question....

Is there not enough room to install these fans as a puller and mount them between the condensor and radiator?

 

[SUMOTOY]

may be a dumb question....

Is there not enough room to install these fans as a puller and mount them between the condensor and radiator?

Not without removing the engine fan. then you might as well just convert to electrics. Move the fan so it contacts the condenser. I used door edge guard on my metal shrouded one. Foam works, as does door sealing rubber found in any yard, or from JCW.

Also, for more wiring options, do a search on "ABC's of 80's Cooling' (Part I, Part II, Part III), either on the main board or the FAQ's. I identify the options to wiring in Part II, and the high pressure switch wiring part numbers in Part III.

SJ

 

[Aids10]

THX M8!

The cooling system in good condition has the capacity to sit in traffic at 115F with the A/C on or climb Sunset point (6 degree 7 miles) at 65 MPH and 100F+ without overheating, so it has plenty of reserve at 75F. The fan will block some flow when it's not running and add flow when running, a design used in many cars, including foreign spec 80's. When the A/C is working it removes heat from the interior and dumps it in front of the radiator, adding greatly to the cooling load.

In hooking it to the compressor it helps the cooling system at the highest load times and improves A/C performance at low speeds. Here in Arizona we run the A/C most of the year, a lot of times including on the trail, so it covers most of our needs. One option that it doesn't cover in this mode is the emergency overheating, where you want the fan running but don't want the A/C on. The A/C comes in the winter to dry the defrost air and the fan is not needed/wanted in that mode. Looking into using a rear heater fan switch with it's on-off-on to be able to turn it off when not needed and have two modes.

Some of the ways to wire the fan;

Running when the ignition is on; Advantages, none. Disadvantages, it runs when not needed putting unnecessary load on the charging system and wear on the fan, slows warm-up in the winter.

Manual switch control; Advantages, driver can run it any time it's needed. Disadvantages, driver has to remember to use it and know/anticipate when it's needed.

Ignition on power, cooling system thermostat controlled; Advantages, runs when the cooling system needs it. Disadvantages, Isn't good at anticipating A/C loads, Doesn't take advantage of after shutoff cooling. This is basically how the fan clutch works, so on our trucks it's just doubling up on one strategy, not taking advantage of others.

Always on power, cooling system thermostat controlled; Advantages, runs when the cooling system needs it and continues after the rig is shut off to help with heat soak. Disadvantages, Isn't good at anticipating A/C loads. This is how most manufactures control the main fan on an electric fan only system.

A/C controlled; Advantages, anticipates A/C loads, somewhat driver controlled, when I am hot and the A/C is turned on, the truck is probably hot too. Great at lowering idle/slow speed A/C vent temps. Disadvantages, Doesn't take advantage of after shutoff cooling. It's not connected to the cooling system, so the truck could overheat and the fan never come on. This is how most manufactures control a secondary fan, either by tapping the compressor clutch or a high side pressure and/or temp switch.

All strategies have compromise, the A/C controlled works the best for us. The advantages for us is that it's easy to wire, no switches or underdash work, nice and simple. The disadvantage is some lack of control, but they are easy to overcome, to turn it off in the winter simply pull the fuse and the Bosch relay we used has two output connectors, so in case of emergency overheating just open the hood and move the power wire to the second output and it's always on.

Sorry for the looonnngg winded reply!

The relay we used is a Bosch #0332019150 five connector, normally open, $5.39. The fuse holder is a Buss Fuse heavy duty blade type #BP/HHG, $2.29. The extra mounting kit is a Derale #13001, $3.87.

After a little more research we are going to add a second relay, jumper the power and fan output between the two and tricker the second relay with a radiator thermostat switch. Then ether or both relays can turn on the fan, it will come on with the compressor and run anytime the radiator is over 200F including after the motor is off cool down.

 

[TexasJack]

The Derale pins were very nice, couldn't break them. Bummer about the Flex-a-Lite ones, but that not the first problem that I have had/heard of from their products.

The tape and pins can be seen in the pix on post #48.

Hotter than Hell in S Tex. - A/C Aux fan install ??!! - Page 3

We used the plastic ones;

http://www.derale.com/elec-fan-accessories.html

Do you think the 3M VHB tape would work well for this application? I use it to attach RFID tags to Oil and Gas assets. You cannot pry them off after the 72 hour setting time. It can handle extremely high temperatures, doesn't become brittle over time and is resistant to chemicals and UV.

 

[TexasJack]

Has anyone here in Dallas affected this modification yet? If so, I'd like to take a look at it.