Okay, so my '12 Accord Coupe is currently at the work shop getting polished so I borrowed my sister's G35 a day ago. It was raining while I was on the highway and as I changed lanes and was about to approach an exit ramp, I started hydroplaning uncontrollably and ending up skidding off the road, down a declining slope and into a small puddle of rain water which I ended up needing a SUV to pull me out. (No cosmetic damages, thank God.)

Long story short, the water was up half way to the wheels (20") when I got stuck there and I spent probably 5-10 mins trying to reverse slowly and forward to try and get out of there. A gentleman was nice enough to stop and pull me up with his SUV with a webbed strap. However, when I got back to the side of the road, I noticed my check engine light came on and the cooling fans cease to work, and when I was driving the car back home ever so gently, I observed the temp gauge going to 3/4 to almost all the way high and then go back to the middle, sort of like an endless loop.

So my questions are,

1. Could I have possibly blew the fuse? How do I check the 40V fuse associated with the fan? (I have no testing tools available)

2. If the fans aren't working at all, what is cooling down the car that's making the temp needle go back to normal every couple of minutes?

3. Is there any other damage that could possibly be associated with being under that much mud? The car is stock. Only on 20" rims with low profile tires. No aftermarket intake, exhaust, suspension or anything.

Thanks in advance for any suggestions or comments.

 

Nothing too serious, begin by using a high pressure hose to clean out the radiator. Sounds like you might have caked on mud from going off road. Fans not working, run it by Nissan and have them check out fuses...Gary

 

Clean your radiator for sure... but don't use a high pressure hose to clean it though because you could damage the radiator. Try using a regular garden hose with a nozzle on it and spray it from the back side forward, so you're trying to push the dirt and mud out from the same direction it came in rather than pushing it through the radiator and lodging debris further into it. Also make sure that nothing is blocking the front grille of the car since this is how the fresh/cool air flows in and gets to the radiator to begin with. The fans in car radiators only come on when the temperature is above a certain very high temperature and usually only when you're moving below a certain speed. If you're moving at a high rate of speed then the car should get plenty of airflow through the front as a result of moving fast. The only thing that would prevent that is a blockage in the front of the radiator in an otherwise healthy and well-maintained cooling system.

Also check the coolant reservoir to make sure it's got enough coolant in it. If it's low, make sure you use the right kind of coolant to fill it back up because many coolants are not compatible with one another and can cause catastrophic damage if mixed within the vehicle.

 

To answer you're second question, the fans don't need to work to cool your car if your car is moving. The fans are for cooling at idle or very low speeds. Otherwise, they don't normally come on when there's 60mph winds thrusting thru your grill, as well as 3k rpms (or so) of engine speed turning your water pump.

 

Thanks for the reply guys. Your help is much appreciated. Today I replaced one of two of the 40A fuses associated with the radiator fan, but had no luck in fixing the issue. My temp gauge still increases frighteningly high at idle.

The other 40A radiator fan fuse is jointly connected to another 50A and 30A fuse block in the fuse box. How do I go about swapping that one out? Would I need to purchase separate fuses for those as well? (The 50A fuse connected I believe is for the BCM.)

 

Honestly, with the assumption that it's the original radiator, all that energy could have easily cracked the 10+yr old radiator. Have you pressure tested it?

 

I haven't, but it looks to be in good shape. There wasn't any caked on mud and dirt when I rinsed it. The day the skidding happened, the rear looked to be more deeper into the water then the front.

However, the fans do not turn run at all. Even when I kick on the A/C unit (which leads me to believe that's the culprit). Plus I live in South Florida so it's been scorchingly hot these past few weeks.

I'm trying to find a way to change the other 40A radiator fan fuse that's jointly connected to the BCM in the fuse box. This is what it looks like.

The farthest 40A radiator fuse has been changed. I'm trying to see how to change the other one since it's joined with two others.

 

I think there is a TSB or recall on certain G35 fan motors. Might be worth looking into that.

 

Will definitely look into that!

Any thoughts on how I can at least try to troubleshoot to see if the other joined fuse is blown?

 

When you sit at idle and turn on your ac, does your fans come on? Seems your thermostat is fine cause it's going back to normal as you drive. I had the problem where both of my fan motors were out and didn't realize it. One on the driver side barely worked as I hit it with the screw driver end and it would barely spin.

 

Just do a continuity check on that 40A fuse with a Volt/Ohm meter. You don't have to change it if checks out good.

 

You can check your fans by applying power and ground directly to the fans. You would need a couple of test leads to do this. Both motors have a 4 pin connector. Pins 1 and 2 are the power pins and 3 and 4 are the ground pins. Pins 1 - 4 and 2 - 3 work together to complete the circuit and make the motor run. For example, apply 12V to pin 1 and ground to pin 4 and the motor should turn.

The reason for the two pin combinations is because one circuit is activated when the A/C is turned on and the other when the engine reaches the temperature requiring cooling. By doing this check you isolate the the fans. If the fans turn, then you have to troubleshoot further. There are different ways to troubleshoot, it all depends on the person's approach to the problem. Do you own a Volt/Ohm meter and do you know how to use it?

 

No sir. None of the fans come on when the A/C is turned on. The thermostat gives pretty accurate readings. When I try to give the two fans a head start with my hands, neither of them give any effort at all to try and spin.

I changed one of the 40A fuses already anyhow just to clear the air with that. Its the other joined fuse that's associated with the radiator fan that's giving my mind a run (I attached pics in my previous post of what it looks like).

Thanks for the diagram and info Wuzz-upp.

Will definitely look into that and report it back to you guys.

 

KngOfHrts, I understood you post and read you had replaced the 40A fuse not joined. You can easily check the joined 40A fuse with a meter without having to replace it if it is good. Try and do what I suggested to test your fans if they work when you power them directly, then I would suspect a relay problem and I will try and help you figure it out. But you will have to have to use a meter or have someone do it for you to do the troubleshooting.

 

your fans will and need to run at any speed you are going. i dont know where scraggle heard that info but thats super false.