Hey guys, so got in the QX4 to drive home from work yesterday and the air wouldn't blow. I could feel it cold through the vent, but not blowing out. Turned the heat on, same thing, could feel heat, barely. but isn't blowing. So I did a search and came to the conclusion that it must be the fan control amp. Problem is, I had the same thing 2 years ago, except it would only blow on high, wouldn't go off, so opposite effect. So I replaced it 2 years ago and it's worked fine since, has anyone else had to replace this part multiple times? I ordered it and should be here tomorrow so I will report back if that's what it is for sure, but I'm feeling pretty confident considering the searches and responses I've seen. Mainly just wondering they heck I'm doing this for the second time and if anyone else has. Have a good one!
Josh
Fan Control Amp
Re: Fan Control Amp
-->> I suggest that you first try starting the blower by giving it a push and see if it goes. If so, bad blower, cheap/easy fix. You'll have to pull it out to do that, but IIRC it is only 3 screws.
I replaced my control amp this winter (2001 QX4) -- had to get the part from a dealer, since I needed to get to snow country, and didn't want to be in bad conditions with no defogger. Worked for 2 days.
Turned out that it was the blower, not the control amplifier. Something was open (brushes?) when the fan would stop in certain positions. If I would start it by hand, it would keep going. Depending on exactly where it stopped rotating when I turned it off, it might or might not start again. I could also measure approximately 200 ohms on the motor winding at certain positions of the blower, whereas it should be more like 1 ohm.
I tried disassembling the blower (hopeless) to see whether I could see what went bad. Damaged the blower, but was stupid enough to hook it up to the controller (control amp) again, which burned out my new control amp (sparks, popping).
Got a new blower, put back in my original control amp (which was never bad after all), and everything is fine.
Blower: http://www.amazon.com/TYC-700044-Nissan ... detailpage
If you want to bother with it, there is a write-up on how to repair your own control amp, which you can do for maybe $15 in parts or less.
DIY repair of control amp: http://www.nicoclub.com/archives/fix-th ... issan.html
I got the parts, but haven't bothered to fix the one I damaged, since the original OEM works.
Control amp: http://www.amazon.com/dp/B00BFE5NN4/ref ... YX8YU05QZW
There may be some change in part number from year to year, so always check.
I replaced my control amp this winter (2001 QX4) -- had to get the part from a dealer, since I needed to get to snow country, and didn't want to be in bad conditions with no defogger. Worked for 2 days.
Turned out that it was the blower, not the control amplifier. Something was open (brushes?) when the fan would stop in certain positions. If I would start it by hand, it would keep going. Depending on exactly where it stopped rotating when I turned it off, it might or might not start again. I could also measure approximately 200 ohms on the motor winding at certain positions of the blower, whereas it should be more like 1 ohm.
I tried disassembling the blower (hopeless) to see whether I could see what went bad. Damaged the blower, but was stupid enough to hook it up to the controller (control amp) again, which burned out my new control amp (sparks, popping).
Got a new blower, put back in my original control amp (which was never bad after all), and everything is fine.
Blower: http://www.amazon.com/TYC-700044-Nissan ... detailpage
If you want to bother with it, there is a write-up on how to repair your own control amp, which you can do for maybe $15 in parts or less.
DIY repair of control amp: http://www.nicoclub.com/archives/fix-th ... issan.html
I got the parts, but haven't bothered to fix the one I damaged, since the original OEM works.
Control amp: http://www.amazon.com/dp/B00BFE5NN4/ref ... YX8YU05QZW
There may be some change in part number from year to year, so always check.
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GrubyFngaz
- Posts: 459
- Joined: Wed Jul 24, 2002 2:31 am
- Car: 2001 Infiniti QX4
Re: Fan Control Amp
attofarad, thanks for the tips/heads up. The part gets here in a little bit, so I will respond back. Wouldn't mind returning the $100 part for a $40 part, that's for sure.
Josh
Josh
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GrubyFngaz
- Posts: 459
- Joined: Wed Jul 24, 2002 2:31 am
- Car: 2001 Infiniti QX4
Re: Fan Control Amp
attofarad, looks like you were right. I took two screws off the fan and tried to spin it and it started up temporarily. Seems like it's just starting to seize up. Well hopefully amazon will take back my fan amp. Thanks for the help.
Josh
Josh
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GrubyFngaz
- Posts: 459
- Joined: Wed Jul 24, 2002 2:31 am
- Car: 2001 Infiniti QX4
Re: Fan Control Amp
Just as a second follow up, I did get the new bower installed with the old amp and everything is as good as new in case any one searches this out later. Thanks again attofarad.
Re: Fan Control Amp
Great that you fixed it! The FSM test procedure is a bit lacking, and will lead one to suspect a control amp in some cases where it is really the blower. Had I found the control amp schematic sooner (linked in my post above), I would have been able to figure out that it was working correctly (electrical engineer/circuit designer) and the blower was at fault.
-Gary
-Gary