Nissan Frontier overheating after electric fan install.

[adrenaline503]

So I installed a Maxima electric fan to replace the clutch fan. Driving around town everything is great, the AC runs cooler at stops and the throttle response is a bit smoother. However, on steep grades at low speeds I rapidly start to overheat. Once I turn the heater on the temperature quickly drops. I have narrowed it down to the following possibilities:

1. The Maxima fan has 2 speeds, low and high. The fan has three power wires. I might have it wired to the low setting but I have been unsuccessful in locating a wiring diagram that clearly shows which wires go to what speeds. Or maybe its multiple wires for high?
2. The e-fan thermostat isn't coming on at the right time. It actuates the fan as soon as the temp goes above "normal" so it seems fine.
3. My cooling system has a problem. I don't think this is the case. Its fine around town and was fine before the install.
4. The e-fan isn't capable of moving enough air to keep the truck cool enough and I am screwed.

So, any other alternate ideas? Anyone know how a Maxima fan is wired?

Thanks

 

[chnlisle]

Put the stock fan back on.

 

[adrenaline503]

Put the stock fan back on.

Yea, thought of that. But back to finding a possible solution for the electric fan...

 

[goodtimes]

I'm not familiar with the maxima fan, but I had very similar problems with a Chevy pickup a few years ago.

After much head beating, it came down to having a properly designed shroud that would pull air across the entire radiator, not just a portion of it. When I took care of this, the situation with my chevy was greatly improved.

In addition to the shroud, I had to fabricate a panel to completely separate the air in front of the radiator, and the air behind it.

Sounds kind of like a "well, duh..." solution....but seriously, the 1.5" gap along the top of the radiator was a problem. At low speeds, it allowed hot air from the engine compartment to be pulled over the top of the radiator, and back through radiator. This was not an issue when moving at higher speeds because of the high[er] air pressure area in front of the radiator. As soon as I blocked this off, my problem went away completely. This gap was originally covered by the OEM fan shroud, which was tossed when I went with an electric fan (after a motor mount failed, allowing the engine to roll over enough that the fan met the shroud, shattering it, and sticking a big chunk of it into the middle of the radiator).

 

[FreeManDan]

http://www.jcwhitney.com/DERALE-ENG...IC/GP_2000833_N_111+10201+600001647_10101.jcw

Summit racing would likely have comparable prices for similar products, but I didn’t bother getting the link...
I have an 03 frontier and the mechanical radiator fan does indeed suck! The A/C is like a refrigerator on the high way, but not so much stuck in traffic.

 

[adrenaline503]

I actually might have found the answer from another forum:

"yellow and black are grounds

green and blue are powers

use any one combination (yellow and blue, green yellow, etc) and the fan will run on low speed

but use all 4 wires, and its on high speed. you can just ground out the yellow and black wires and then run the green and blue jointly through the relay and it will run on high. a relay has 4 posts on it. one is ground. one is trigger, and the other 2 are the actuall switched wires. the battery is connected to one side and the fans; the other."

So it seems that if i combine the green and blue wires then I will be on high speed and pull more cfm through the radiator.

 

[t0mills]

I actually might have found the answer from another forum:

"yellow and black are grounds

green and blue are powers

use any one combination (yellow and blue, green yellow, etc) and the fan will run on low speed

but use all 4 wires, and its on high speed. you can just ground out the yellow and black wires and then run the green and blue jointly through the relay and it will run on high. a relay has 4 posts on it. one is ground. one is trigger, and the other 2 are the actuall switched wires. the battery is connected to one side and the fans; the other."

So it seems that if i combine the green and blue wires then I will be on high speed and pull more cfm through the radiator.

Give that a shot and see if it helps.


I've never had much luck using e-fans on a truck/utility vehicle. Even the really expensive FAL fans ($450+) will be easily outdone by an engine driven fan.

One thing you might consider (if you can't get the efans to work), is to put a singe e-fan on the front of your radiator/condenser to compliment your engine driven fan.
That's the OEM setup on my suburban (with the heavy tow package), and it works great. The only time that it ever kicks on, is when I'm sitting around idling with the A/C on. It helps to push air through the condenser, and make the A/C colder.

 

[adrenaline503]

Okay, I have some interesting news:

-Doubling the wires (black and yellow / green and blue) does indeed increase the fan speed and draw more air through the radiator. I would say at LEAST and additional 50%.

Despite the improvement I was still running to hot on the fire roads. I got further up the mountain than I have before, but I still had to turn the heater on to cool off. As I was getting more and more pissed off my lovely wife asked what would happen if I ran the AC. I told her that it was a stupid idea since the AC only puts more strain on the engine. But, then it occurred to me it would force the fans on so at least I could eliminate limited air flow as a possibility. Behold, no more overheating. I went on the crappiest steepest roads in 4-lo at under 5 mph and my temp gauge didn't move at all. Not to mention I was sitting in a nice cool breezy atmosphere.

So, its the thermostat switch that's the problem. It isn't turning on the fans soon enough, and once they kick on they aren't able to cool the overheated fluid without the additional help of the heater. I am thinking that a higher quality inline thermostat switch should fix the problem. In the mean time, I can just run the AC. In the future I will wire it so I can force the fans on via a switch in the cab. That way I can ensure that my fans are running when needed, or rather when I want. Some might ask why I don't throw the clutch fan back in and save myself my trouble. Well, I am stubborn and want electric fans so that is that.

Thanks to everyone who had suggestions, it got the gears in my head turning. If anyone knows of a decent inline thermostat switch I would appreciate the heads up.

 

[FreeManDan]

You could hit up the local parts stores, I once got a 10" fan from O'Rielly for $60 but could have dropped 90 for one with a thermostat, but thems 1998 dollars! Or do a google products search for "radiator fan thermostat", some are kits with relays, some stick in the radiator fins, some clip to a puller fan, ect. On my first car I rigged up 2 fans, one to come on when the car does and one a switch I hit in the summer, I found in worked best that way for me

 

[BiG BoB]

You don't seem to mention it anywhere in the thread, but was the vehicle perfectly fine with the engine driven fan?

If it was, go back to it! If it aint broke, don't stuff around with it...

 

[ntsqd]

Look up the VDO catalog and find a temperature switch with the rating that you want. These are not much more than a threaded plug with a terminal on the end. Can order them from Summit or possibly a LAPS if you have one with counter folk who know what they're doing.

Use the switch to ground the control side of a Bosch type relay and turn on the fan(s). Since you have a two speed fan you can use two switches of different temp ratings with two relays for a staged system.

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All of that aside, I'd also be inclined to also go back to the mechanical fan, and supplement it with an auxiliary fan that via a relay comes one with the A/C clutch. That should give you the best of both worlds.

 

[dust devil]

From experience, electric fans are rarely anywhere near as effective as a stock fan. Worse, most fans and their partner thermostat switches are manufactured as auxiliary devices, that is, they are intended to come on at some pre-set temperature, usually at or above the temperature of the engine thermostat, in order to boost the standard system at the high end of demand. They are not intended for 100 percent duty cycle or as primary devices. If you don't have an engine-driven fan running all the time, having even an efficient e-fan come on at or above the engine thermostat temperature won't work.

The temperature of the coolant returning to the engine needs to be 30 degrees or more cooler than the coolant entering the radiator in order for the radiator to keep up with engine demand. If the fan stat comes on around the same temperature as the engine thermostat (or higher in some e-switch applications), the engine will be demanding cooled water, but will be getting hot water or only marginally cooled water unless you are traveling at highway speeds because of limited or non-existent air flow. Even when the engine thermostat is closed so that water is not circulating, air needs to be moving over the radiator to bring temperature of the stalled coolant down prior to demand. This virtually requires that if you have only an electric fan, it needs to run all the time.

Having the electric fan running all the time about negates the use of the electric fan to start with. Even really good e-fans produce only 3,000 cfm or so, which is far below a good stock fan, and the electric they draw challenges the alternator, which is harder to spin under load. Nothing in thermal dynamics is free. The trade off in power consumption between a good stock belt driven fan and a high performance e-fan is so slight that it makes no sense to change to electric as your primary system if you have any cooling issues whatever. I can't recall any manufacturer who uses only an electric fan for primary cooling, and most high performance systems that use electric fans from the manufacturer use more than one in combination with a good belt driven fan.

I would limit the use of an electric fan to the role of auxiliary cooling and leave the full-time air moving to the stock fan. The problems you are having are predictable, in my opinion. I have had them also, and every time have had to go back to a stock fan or some combination of stock/electric to achieve adequate cooling in off road use.

 

[adrenaline503]

From experience, electric fans are rarely anywhere near as effective as a stock fan. Worse, most fans and their partner thermostat switches are manufactured as auxiliary devices, that is, they are intended to come on at some pre-set temperature, usually at or above the temperature of the engine thermostat, in order to boost the standard system at the high end of demand. They are not intended for 100 percent duty cycle or as primary devices. If you don't have an engine-driven fan running all the time, having even an efficient e-fan come on at or above the engine thermostat temperature won't work.

The temperature of the coolant returning to the engine needs to be 30 degrees or more cooler than the coolant entering the radiator in order for the radiator to keep up with engine demand. If the fan stat comes on around the same temperature as the engine thermostat (or higher in some e-switch applications), the engine will be demanding cooled water, but will be getting hot water or only marginally cooled water unless you are traveling at highway speeds because of limited or non-existent air flow. Even when the engine thermostat is closed so that water is not circulating, air needs to be moving over the radiator to bring temperature of the stalled coolant down prior to demand. This virtually requires that if you have only an electric fan, it needs to run all the time.

Having the electric fan running all the time about negates the use of the electric fan to start with. Even really good e-fans produce only 3,000 cfm or so, which is far below a good stock fan, and the electric they draw challenges the alternator, which is harder to spin under load. Nothing in thermal dynamics is free. The trade off in power consumption between a good stock belt driven fan and a high performance e-fan is so slight that it makes no sense to change to electric as your primary system if you have any cooling issues whatever. I can't recall any manufacturer who uses only an electric fan for primary cooling, and most high performance systems that use electric fans from the manufacturer use more than one in combination with a good belt driven fan.

I would limit the use of an electric fan to the role of auxiliary cooling and leave the full-time air moving to the stock fan. The problems you are having are predictable, in my opinion. I have had them also, and every time have had to go back to a stock fan or some combination of stock/electric to achieve adequate cooling in off road use.

Okay, that has to be the most useful explanation that I have seen about this subject. The original reason for installing the e-fans was a widely reported increase in gas mileage. That did turn out to be true. The reasoning was that the drag of the clutch fan was eliminated. I knew that the increased load on the alternator would create some drag of its own, but it would be less than than the clutch fan.

I know there is no free lunch. I got the fan for cheap and thought I would give it a shot.

 

[FreeManDan]

From experience, electric fans are rarely anywhere near as effective as a stock fan.

I would have to respectfully disagree sir, here is a list of my experience with my cars, family and friends' cars.
89 Buick lesaber 3.8l v6 with a 10” Hayden fan and 8” junk yard fan from cutlass or fire chicken or something, way more then adequate (even when the AC actually worked).
89 Isuzu trooper 2.2l turbo diesel with 12” Hayden fan, more then adequate.
93 Isuzu Amigo 2.6l I4 with 12” Hayden fan, more then adequate and far superior then stock mechanical fan.
88 F150 with 2 12” summit racing fans, adequate even for medium duty towing.
90 or 91 mustang 5.0 with 2 10” fans, adequate for armature drag racing and daily driver (although he did have to upgrade his alternator).

The only reason a Nissan Frontier v6 CAN’T have an electric fan would be the addition of other electric accessories out running the alternator. We could easily theorize a Maxima fan isn’t up to the task due to its variable speeds.
When you by a fan it should say how big of an engine it can cool, for example 14” Hayden fan should cool up to a 351 cu engine.

 

[ntsqd]

Rather than engine size, fans should be rated for the horsepower level that they can cool. Fuel = horsepower = heat. More fuel, more horsepower, more heat. Even that is kind of sketchy because an overly adequate or inadequate for the application radiator will skew things, possibly considerably.

I've had mixed results with aftermarket fans and tend to shy away from them. The OE fans (particularly the later models like the much vaunted and commonly used on Class 1 desert racers & comp crawler buggies "Taurus" fan) that I have used in the past have been superior to any aftermarket offering that I've seen or used.