Blower intermitant

2000 Nissan Maxima GLE. My blower fan for the ac/heater has been acting oddly. Last week, it stopped working completely. The ac and heat work, just no fan.

Anyways, I have replaced the relay and the blower fan. Everything worked today for about 30 minutes, then it stopped working. Now is where I am at a loss. I had the heat on (85 F) and then turned it down to 78ish or whatever. The fan stopped blowing. No matter what temp I turned it on afterward, still nothing.

So, I turned the air down to 65 F and then five minutes later, the blower comes back on and works.

So is the blower resistor bad? Why is it doing this?

I would guess bad resistor and here’s why: the resistor pack lives inside the HVAC ducting in your dash (on most cars, I assume yours is the same). Probably there is a bad connection or a break in the resistor such that when it gets very hot, it stops passing current, and when it cools down (cool AC on) it begins working again.

There is one doubt that I have here, and it’s this: usually, when you have the fan on Hi speed, it bypasses the resistor completely and receives full current. A bad resistor frequently shows itself as having only high speed. Perhaps you have a sticky fan motor or failing fan speed switch.

Sorry I can’t be more specific, you’re going to have to do some testing.

It is possible that you have a intermittent bad winding in the blower motor. Try connecting power directly to the blower. Run it for 30 minutes or so and see if it quits.

It’s not that. The blower fan is new, the old one worked too and I had the same issue. I am wondering if the resistor has some sort of crack that when it heats up, I would think that is would work better versus when if it was hot and then I turned on the AC then it would stop working. That makes more sense. The issue is that though the fan will not run as all (even on high) when it is dead.

It’s just odd that it stops working when it gets hot.

It’s going to take some fault tracing. If the original problem was in fact a bad blower motor it’s possible the motor dragging for so long before it quit may have burnt the fan speed switch up.
A dragging motor draws a lot more current than a good motor and since current means heat it could have been cooking the switch for a long time and the switch has now decided to drop.

It’s also possible the switch could have been the problem all along.
Another possibility is the wire connectors on the blower motor terminals and at the resistor block could be burned and making a poor connection, but I assumed you checked the wire connectors when the blower motor was replaced. And the fuses.

I have checked everything but the resistor and the switch. Where is the switch located? Everything checked out though which makes me more curious. There isn’t but so much in there to replace. So far I am out only $125 ($100 blower and $25 relay). I just want to figure this out. I plan on keeping the car for a few more years.

The problem might be with the vent control module. This module measures the tempurature in the passenger cabin. When a temperature is set on the controls, this module turns on the blower fan if the temperature goes below or above the temperature setting. Depending if it’s in the heat or air conditioning mode. Sometimes the temperature sensor on the module fails where it doesn’t measure the temperature properly so it fails to turn on the blower fan.


I think Tester is correct. Here is what he’s talking about.,carcode,1359222,parttype,7000,partGroup,24

An update. This morning I started up the car to go to work. It was 35 F outside. I turned on the car, had the heat on, about 15 seconds later, the fan stopped blowing again. I could not get it to come back on on the 20 minute ride to work. When I got to work, I pulled out the blower resistor and put it back in, then the fan came on. I ran it on high for several minutes at full heat full blower. Then adjusted it at various fan speed settings and temps and it worked.

Is there any way to test the resistor itself with a volt-o-meter. I have continuance on it.

BTW, where is the ambient air temp module located?

If I had an 01 Maxima, I would also have the factory shop manual & electrical troubleshooting manual for it & could tell you for sure, but I would’nt be surprized if theres a way to put the auto climate control system into self test mode.

On some fords the self diagnostic mode is entered by simply pressing and holding 2 of the buttons on the control panel. After a few minutes any troubles that are detected are displayed as codes on the dash display

See if you can get the computer to tell you what it’s problem is.

Sounds like an idea. Anybody know how and if the Maxima can do this?

You can check the resistor using a meter. One way to check it in a live circuit is to place the meter probes across the wire connections to the resistor block while the meter is in the DC volts function. Then see how much voltage is across the resistor while the fan is supposed to be running. I would guess the resistor may drop 1 or 2 volts across it when the fan is running. If the resistor opens up then most of the voltage will be dropped across it. Usually a resistor will open up when it is bad and so it doesn’t work again later. I don’t think the problem you are having is with the resistor pack but it could be with a connection to the resistor pack itself or the system controller or, the switch.

I’m thinking it is not the resistor either. There was some brown stuff with looked burnt around the plugs on the resistor but I scraped that stuff away and it seems to be working. I did find the self-test procedure online and everything is within normal parameters (but the fan is working). I need to try it when and if the fan goes out again. I will paste the procedure below for anybody else that might need to use it in the future:

To run a self-diagnostic for the DCC:
Turn engine on. Within 10 second of starting engine, press and hold ?OFF? button on the ACC for 5-10 seconds until all segments on the display light up.
Test 1- Display Test. Look for any missing segments or icons
Press Up arrow to get to Test 2.
Test 2 ? Input signals from each sensor Wait a couple seconds and it?ll display error codes (20=all ok, 21=ambient, 22=in-vehicle, 24=intake, 25=sunload (test in sunlight to prevent this error), 26=PBR)
Press Up arrow to get to Test 3 or Down arrow to get to Test 1
Test 3 ? Mode Door Motor This test takes a little longer. 30=all modes ok, 31=vent, 32=B/L, 33=B/L, 34=Foot/Def 1, 35=Foot/Def 2, 36=Def
Press Up arrow to get to Test 4 or Down arrow to get to Test 3
Test 4 ? Actuators Test Pattern Toggle modes 41-46 by pressing defrost button on ACC.
Test 5 ? Temperature Readings Press defrost button to toggle through sensors (ambient, in-vehicle, intake in that order). If the temp is -22, then that sensor is not working. The temperature can also be adjusted to compensate for differences between temp setting and the temp felt by driver. It can be adjusted 6 degrees up or down. While in Test 5, press the fan switch and then the temp adjustment can be made using the Up/Down arrows.
Hit Auto button or turn car off to exit self-diag.