Smokin AC

[GunMentalGrey]

Anyone else had an AC part burn out in the cab? Looking for hints as to where to start looking.

This morning jumped in the Nav and by the end of the street could smell that special electrical fire smell. Quickly stopped, turned off and figured it was coming from the centre of the dash area. Thought it might be a phone charger but it wasn’t hot or smelly. Moved off again and the smell was still there. Stopped again and checked. Couldn’t work it out. Third time smoke seemed to visibly come out of the air vents. Stopped yet again and pulled the fuse for the AC system. Seemed to stop the problem.

Have pulled out the centre dash surround and no signs of electrical shorts or bad smells apparent. Drove for a fair bit longer without a demister and no further bad smells.

I guess the next step is checking the fan motor or similar. It’s raining now so will go look properly later.

Anyone else experienced similar or got hints as to where to look?

 

[Old.Tony]

Under the dash in the bottom of the air conditioning duct (passenger side) there'll be a small removable section about 1cm wide and 5cm long. Undo it, remove it. This is the resistor pack for the fan blower - a common failure item.

 

[GunMentalGrey]

Of course. I’d already replaced this previously. When I check it was black and sooty, but didn’t appear particularly burnt or melted. Will try reinstalling the fuse and see if it lets out any more smoke.

 

[fuzzylogic]

The bottom bearing of the fan motor? With all the rain that's been happening, a bit of water can get in, rust up the bearing, and maybe it's seized, and spinning in it's plastic housing? It would also explain the recently burnt out fan resistor...

 

[GunMentalGrey]

Finally got a few minutes of motivation combined with no rain. Put the fuse back in, turned the fan on and the smoke came out again. Pulled it out and found the fan almost seized. Problem almost solved. Will try to source a replacement. Not sure it’s worth trying to repair bearings when the magic smoke has been escaping.

 

[fuzzylogic]

I bought a cheap blower off eBay, came with a fan resistor card too, I think about $130 delivered. It's actually a better design, which doesn't allow water to drip through the motor. It's been working fine so far. My d40 likes to be parked without the front left being the lowest point. When it belts down with rain, the drain hole in the plenum can't cope, and it spills into the air intake, dousing the fan, if the front left of ute is the lowest point... magic smoke almost sounds like it's worth inhaling

 

[GunMentalGrey]

I bought a cheap blower off eBay, came with a fan resistor card too, I think about $130 delivered. It's actually a better design, which doesn't allow water to drip through the motor. It's been working fine so far. My d40 likes to be parked without the front left being the lowest point. When it belts down with rain, the drain hole in the plenum can't cope, and it spills into the air intake, dousing the fan, if the front left of ute is the lowest point... magic smoke almost sounds like it's worth inhaling

Mine also parks outside a bit nose down. I’ve ordered a wrecker replacement today. Should be in tomorrow.

When I think back it was getting a bit noisy.

 

[fuzzylogic]

Mine would sound like there were dry leaves caught in it, actually bearing having a hard time, try parking other way, if possible. I've had my ute for over 8 years, about 4 fan resistors in that time. Parking it tilted to the right helps heaps. Don't hear water swishing around as often after big rain...

 

[GunMentalGrey]

Plugged in the new fan and got .... zero movement. Checked the fan load resister and while it looks like it’s got a coating of smoke all circuits seem to be complete with no damage. It was getting hot when I tested and found the fan was seized. Hope I haven’t fried some wires in the belly of the beast.

 

[GunMentalGrey]

It’s been to long but made some effort and now I’m not getting significant voltage on the fan connector. Neither old car nor new (wrecker part) seem to want to go. Quick test straight off the battery got it spinning nicely so it’s not the fan.

There is power to the control unit the wires I can see don’t seem burnt.

Is there another fan fuse/relay somewhere?

 

[GunMentalGrey]

Solved. Ferreted around under the bonnet and found two blown fuses in the fuse block just in front of the driver. Replaced them, put everything back together and it works again.

Next problem: airbag light still flashing after replacing the clock spring. (Which I’m going to search the forum for shortly)

 

[fuzzylogic]

I was wondering if the beast's belly would reveal it's secrets, good old fuses... don't know anything about clock springs, touch wood, mine's never had a problem...

 

[GunMentalGrey]

It only occurred to me late that the tiny fuse in the cabin didn’t seem big enough for the size of the wires headed to the fan and fan load resistor.

Next car maintenance day I might pop the airbag back off again and make sure I plugged it in correctly after replacing the clock spring.

 

[Old.Tony]

The other possibility is with the airbag is the diagnostic module. In mine, this sits under the console behind the trans shifter. You have to remove the cup holders to get to it - thankfully not too difficult to do. You'll need a Torx-50 bit to remove it. Nissan wanted over $1K for this new, I took a chance and got one from a wreck that hadn't triggered its airbags for $100 and it worked a treat.