[Claire Hund]

Hello, I have a 2002 Frontier supercharged v6 . Been having some issues with overheating and I think it might be the fan. I'm pretty sure it's an aftermarket fan because the previous owner did a lot of add ons. There seems to be a few stray wires but I don't know Anything about wiring. I also read somewhere to check if it turns on when you have the AC on full blast with the car running which it didn't. I also noticed when I tested that, that the AC wasn't very cold, which is a more recent discovery after the overheating started.
I replaced the thermostat and it didn't help.
The water pumped seemed to be pushing coolant around when I did a cold start with the radiator lid off. Not positive on that one though.
Whe I took it to the dealer they told me the radiator and condenser needed to be replaced and quoted me $1,200 so I stubbornly wanted to explore it more myself.

There's also a chance it could be the coolant/water ratio because I added some water to it the first time it overheated.

Can anyone help me see if these wires are possibly the issue and where they might go?

Also, could just a fan and/or coolant ratio contribute that heavily to a truck overheating ?
Started off doing that when going through a mountain pass that inclines for a while. Now it happens after about 15 minutes in town.
It's also high 90's weather here right now.

Here's some pictures.

 

[smj999smj]

The fan you have behind the radiator is certainly an aftermarket electric fan. From the factory, there would have been a mechanical fan with a fan clutch and a radiator shroud that completely covered the core. Some Frontiers did have an auxiliary, electric fan in front of the condenser, but not all. I have a 2003 SVE (which has the supercharged VG33ER enginee) with A/T and factory A/C and it doesn't have the electric fan.
It's one thing to add an electric fan, but you have to make sure it pulls the proper air-flow through the cores. It likely doesn't come on with the A/C because they never wired it properly and they only come one at a certain temperature.
If it were mine, I would remove those electric fans, relay and mess of wires and either sell it or toss it in the trash. Then I would go get a factory shroud, fan and fan clutch and install it. At least then you would know the fan was designed to pull the proper air flow to cool your radiator and condenser cores. It's been around 100 degrees F. where I live and my coolant gauge needle never goes past halfway and the A/C is blowing ice cold!
Rockauto actually sells the shroud for $45. The lower shroud you can get from Nissan, P/N 21477-7B400. Aftermarket fan clutches have a bad reputation and most fans that you'll find in a salvage yard are cracked, so I would also get from Nissan:
Fan clutch 21082-5S700
Fan 21060-4S100
Bolts 08156-62028 (need 4)

Whether you need the radiator and A/C condenser or not, I can't say. If there are signs of leakage, core fin rot or a lot of bent over core fins, by all means replace it! Also, don't overlook the radiator cap! A cap that is not holding the proper amount of pressure will lead to overheating. If you replace any coolant, make sure you properly bleed the system of air. As far as having too much water in your coolant, it won't be good for freeze protection, but it's not going to cause you to overheat.

 

[The other Sean]

Just to clarify, the OEM mechanical fan has been removed and a set of electric fans were put in their place?

I would go with smj99smj's advice. Unless you have an electric fan capable of pulling enough CFM's and has proper shrouding ($$$$ btw.....) then that is a large part of your issue. The P.O. probably added the electric fans hoping for more power or MPG's. I would swap back on the mechanical fan and proper shroud and go from there.

 

[smj999smj]

Yeah, if you look at the first pic, you clearly see the water pump pulley and there's no fan on it. In one of the other pics, you can see that the shroud doesn't cover but about half of the core surface.

 

[Skibane]

Yep - It's hard to find an aftermarket fan capable of moving anywhere near as much air as the original belt-driven fan.

Also - this is a wild shot, but...Have you confirmed that the electric fan is actually pulling air through the radiator, rather than blowing it back the other direction? If the original owner wired the fan incorrectly, the blades would spin the other direction - resulting in the fan working against road wind, rather than with it.

 

[Claire Hund]

Yeah' there is no factory fan, only the aftermarket one.
What do you mean about the water pump pulley not having a fan on it? Is there a separate fan that should be cooling that?
Sorry, still learning a lot about auto mechanics.
I think I will look into getting a new factory fan/shroud/etc.
So would a faulty fan be enough to cause frequent overheating? Just wondering if I should try replacing anything else too.

Thanks for the help!

 

[smj999smj]

The fan (mechanical) bolts to the fan clutch, which bolts to the water pump flange, sandwiching the water pump pulley between them. The crank turns the crank pulley, which moves the fan belt, which turns the water pump and fan.

 

[The other Sean]

Yeah' there is no factory fan, only the aftermarket one.
What do you mean about the water pump pulley not having a fan on it? Is there a separate fan that should be cooling that?
Sorry, still learning a lot about auto mechanics.
I think I will look into getting a new factory fan/shroud/etc.
So would a faulty fan be enough to cause frequent overheating? Just wondering if I should try replacing anything else too.

Thanks for the help!

The current fan setup is the most glaring issue. I would swap back to the mechanical fan first before throwing any more parts at it.

 

[Cusser]

The current fan setup is the most glaring issue. I would swap back to the mechanical fan first before throwing any more parts at it.

I'm agreeing with this, like the others have stated. Likely someone added the electric fans because the original fan clutch was bad, or they thought they could gain 2 hp.

Even "IF" both those electric fans are spinning, and they are pulling air through from the front, still not a great set up. I think a dealer recommending a new radiator and condenser is ridiculous, air flow is #1 importance for both of those (engine cooling AND AC performance). The fan shroud is an important and necessary part !!!

 

[Claire Hund]

Thanks for all the great information everyone. I think I will focus on getting a new fan set up for now. I am taking into a local mechanic on Monday to do that. Not sure I feel comfortable messing with the wiring and all that