overheat still

[crankor]

After replacing the water pump, did a test drive and prob after about 2 hours of n off driving, cars temp started going up again. I'm getting a combustion kit to check for fuel mixed with coolant but I think the shop I had search for the leak originally ruled out the head gasket. So my questions... I didnt realize till now that my ac compressor is going. It only circulates while driving and I wonder if that could cause that
...the other thing is I still can't get my radiaor fans to turn on. The only thing I haven't replaced were relays but I have no idea what one is related to that. There's only 1 in the box by the battery. I don't seem to be losing coolant anymore.

I'm not 100% sure but think I smell coolant in the vents....guess that means a bad heater core... are there any more obvious ways to verify that? Guess I'll start figuring out how to take this dash apart

[VStar650CL]

Coolant coming out the vents could just be vapor escaping when she heats up. The human nose can't discern antifreeze at 1 ppm like gasoline, but it still only takes a vanishingly tiny quantity to smell it, typically 60 ppm or about 1 part in 17000.

If the AC is running but the fan isn't, chances are the car is going to overheat fast during prolonged on-off driving. That's no surprise. In fact your compressor is a swash plate type which runs constantly whether it's doing much cooling or not, so it's even less of a surprise. If it's overheating you, put the mode select in a non-defrost position and turn the AC switch off. That will kill the clutch.

Your fans are variable-speed PWM types like a lot of Infinitis from that period. When both of them quit at once, it almost always means the fan controllers have gone south.

[VStar650CL]

PS - Diagnosing the fan isn't rocket science, although you'll need to use the '10 FSM (the '11 and '12 versions here seem to be missing the EC section). You can find the wiring diagram on EC-1150 here...
https://www.nicoclub.com/service-manual ... 0%2FEC.pdf
...and the fans are on the very first page. With the key on you should see 12V between pins 1 and 3 on each module (1 is power, 3 is ground), and when the engine gets toasty you should see a rising voltage on each pin 2 (the PWM wire from the IPDM). If you have all that, the controllers or fans are shot. You often find both out of commission for the same reason as two burned out headlamps, people simply don't notice the first one failing until the second one burns out and they're driving blind (or overheated, as it were).

[crankor]

I did replace the fans and the control module but still nothing. I haven't checked the wiring itself yet though. ill do that next. Looks like this year doesn't have a fan related relay then?? Guess it didn't overheat the first 3 months cause i always had the heater on. I was going to bypass the heater core temporarily just to rule it out and check the back hoses for leaks since one of them did already explode on me. I did see there is a 50 amp fuse for the fans but it looked fine.

[crankor]

AH the pmw relay does control the fans....

[VStar650CL]

There's a relay for each fan, and the coil on Relay 1 is powered by its own fuse #42 in the IPDM. If that fuse blows then neither fan will work for reasons I'll explain below. Upstream, there's also a separate 50A fusible link for each fan, but the kink is, the coil for Relay 2 is powered by the output from Relay 1. That means if fan 1's fusible link fails or Relay 1 fails, neither fan will run. If that's the case, you'll find no 12V power at pin 1 on either module. The other thing which is common to both is the PWM line from the IPDM, and it's not impossible that the IPDM has a blown drive FET. While I don't deal much with Infinitis (I'm a Nissan tech), my understanding is that those modules have a "full speed failsafe", so the only sort of "blow" which could disable both fans is a FET that's melted short, not open. In that case you'll find 0V on both pin 2 PWM wires no matter how hot the engine gets.

[crankor]

The big issue i was having is the diagrams i found dont match what i have for relays n such. I only have 1 relay in either side of the two boxes (one being the PMW). In any case, i somehow got them to turn on. Not really sure what i did to do that. I did check two fuses under the dash that were 20 amps that i forget what they were called but they didn't seem to of been related but i pulled them out to check and dropped one i couldn't find then replaced it with a spare (but they both looked fine...) the other thing i did was unplug and replug in the one relay on the drivers side which seemed to be labeled for the braking system ... I did check the plugs first and they were getting 12v

SO yah problem is finally fixed. Now onto the exhaust and then wheel bearing

[crankor]

So if I wanted to replace this for good measure,any idea what to replace it with? Does it have to be a specific type of relay or is a relay a relay as long asthe volts and amps match? I'm not even sure what this one does but it's the only one I touched to get the fans working

[VStar650CL]

Yah, I'm finding two different sets of documentation here and in ASIST. The '11 PDF shows the same as the '10, but the EWD shows a single relay with a single C/U for both fans. But the fusebox in the ESM shows a "Type A" and "Type B", which makes me think there may have been a mid-year change. Does your system have a separate controller for each fan, or just one controller connecting to both fans?

Now here's the really weird part, Both types show the relay you played with being "Horn Relay 2". Absolutely nothing to do with the fans. They also both show a "Cooling Fan Relay 2" in a different box, but the EWD shows Relay 2 shouldn't exist on the type which has a single fan controller. If it exists on your ride, it will be in a small F&R box tacked to the passenger fender someplace aft of the headlight, containing a 50A fusible link and a relay, nothing else. It's E212 in the diagram below, to orient you.


They don't actually show where to find Fan Relay 1 (which will exist on both versions), but it's someplace near the main F&R box. The below harness layout is the best I can find, the location is tagged in green. The VVEL Relay is right next to it:

11 FX Fan Relay 1.jpg (68.55 KiB) Viewed 492 times

[crankor]

i couldn't find anything labeled fan anything other than the 50amp fuse thats in the same box as the sole relay (the PMR?) on the passenger side in front of the battery. So i assume theres only one controller for both. Hard to tell exactly what thats pointing at in that diagram.

[VStar650CL]

I agree, this documentation is awful. I expect better from Nissan, their WD's are usually pretty good. For some reason these are very deficient.

Anyway, you need to look at the fans themselves to see if the C/U is single or dual. If they're dual then you'll have one C/U with two fat wires and one skinny going in, four fat going out to the fans. If they're single then everything on each fan will be duplicated.

[crankor]

Revisiting this.... So once again my fans are not turning on. Car atleast hasn't overheated yet while driving but i'm sure it would at idle. I Still Have no clue what is suppose to actually turn on the fans. The scan tool shows the fans being on when the a/c is on but they just aren't actually on. I can try replacing the two relays i have i guess although im not really sure what part to replace them with since the ones i found are for the 1st gen. The one on the right with the picture is suppose to be the acc brake relay and the one on the left is the pmw relay. It can't be a fuse since it WAS working that one time. Also not sure if it's relevant but the a/c doesn't kick on until i start driving. Though it DID start right away when the fans were working that one time.... is it possible the ac compressor itself isn't doing something it should as far as signaling?

-some time later-

Ummm so i think i figured out what the issue is currently. The dumb lock on the main connector to the fan control module must be broken cause the plug was practically off WEll the fans work again lol guess i'll have to duct tape it on or something