Amelite

Hey guys,

I have a 2003 350z. I've owned it for 2 years and has approximately 100k miles. I'm experiencing my first problem since owning the car and I need help diagnosing it.

Earlier today, I was driving and felt a slight "bog" in 6th gear. I shrugged it off and drove for another 2 miles and then parked. Two hours later, I try and start the vehicle and it gives me trouble but eventually starts, but the service engine soon and slip light both came on. As I'm driving home, I notice the car overheating within just a few minutes. I crank the heat and drive to the nearest auto parts store. I ran an OBDII scanner and came back with a P0340 code. I believe the camshaft positioning sensor went bad due to overheating. I then realize neither fan is turning on, even with the a/c on high. I checked the fuse-box adjacent to the battery and see the fl40a relay/fuse is blown. This is the one that controls the removable top and radiator fans (mine isn't a convertible). I pulled it out, but the auto parts store didn't have it. I decided to limp the car home and look online for the fuse/relay. However, I cannot for the life of me figure out where to buy this item online.

Anyways, if someone could chime in with advice as to what the problem might be, other than the blown fuse/relay and where to purchase said fuse/relay, it'd be much appreciated!

Amelite

Update: I changed the 40-40-40 relay in the battery compartment and the passenger-side fan is now spinning. My a/c is also working again. However, the driver-side fan still isn't kicking on. Am I incorrect to think that both fans should in fact be spinning when the a/c is on? I'm going to replace the cmp sensor later today and I'll update.

EDIT: Driver's side is now spinning as well. Looks like the 40-40-40 did the trick! $27 part from my dealership. I'll be doing the cmp sensor - bank#1 later today.

Amelite

Okay - I just got back from the auto parts store. Unfortunately, the 40-40-40 I just purchased from the dealership is already blown. Is an exposed wire the only possible cause for this 40-40-40 to continue to blow?

Syner

It sounds like a short to me...

travlee

iTrader: (8)

electrical gremlins are always fun to try to track down

Amelite

Yeah, I just can't find the short anywhere. Only one part of the 40-40-40 is blown, which is the furthest right portion.

Amelite

Is there a chance that the fan motor is causing the relay to blow?

Amelite

The car is bone stock and has never been in an accident. I'm finding it hard to believe it's a short, considering I've never even taken a wiring harness off on this car. What do you guys think about a potentially bad fan motor causing the relay to be overpowered?

Syner

If it seizes, it could be...

Amelite

**Update: Relay literally welded itself back together and works. I also installed the new camshaft positioning sensor, which handled the rough start.
Now, when I turn my a/c on, one of the cooling fans sounds like it wants to fly away from going so fast. Is this a sign of too much current going to the fan or is it due to a faulty water pump, which is making the fan work harder?

rcdash

iTrader: (18)

One or both of the radiator fans are bad. You will need to change them as they are drawing too much current and fusing your relays. The fan can seem to work just as well with a bad bearing but usually you can hear that one fan is a little noisier. It will start to melt wires, relays, and blow fuses as the current draw increases...

Amelite

Thank you very much for the reassurance! Is there a brand you'd recommend buying? When I purchased the car 3 years ago, I had the dealership replace the fans before making the purchase. So, I don't think I want to go the OEM route again.

travlee

iTrader: (8)

are you sure they put OEM on there?

Amelite

I just figured dealerships would use OEM.

travlee

iTrader: (8)

there is no guarantee, and it would depend if a reputable dealership or a smaller mom and pop one..... make sense?

Amelite

It's a pretty massive dealership that is paired with Kia and Volkswagen. However, you very well might be right about them not being OEM. I'll take a peak tomorrow morning and update.

Though, wasn't there an issue with OEM cooling fans in the earlier years, or am I mistaken?

travlee

iTrader: (8)

don't get me to lying......

Amelite

Okay - I just ordered the Mishimoto cooling fan kit with the direct plug-n-play harnesses. I'll update in about 5 days with the results.