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AC Blower doesn't work on low and mid speed


HairyKnuckle's Avatar
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09-28-04, 04:13 PM   #1  
AC Blower doesn't work on low and mid speed

The blower motor under the dash is not pushing out air (AC or Heat) when the rotary dial dash switch is in the low or medium setting. It works in the high setting. I replaced the blower resistor from under the dash but that didn't help the situation. The old resistor that I removed did look like it was burnt. I also checked every fuse under the hood and under the dash that was marked fan or blower. (2000 Nissan Quest AKA Mercury Villager)

Could my rotary dashboard dial switch be bad and how do I test this?

 
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09-28-04, 04:25 PM   #2  
I'd start by checking the new blower resistor to see if it looks burnt. You may have something wrong causing this to happen.

 
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09-28-04, 04:36 PM   #3  
Yes the switch could be bad check for power at different terminals at the blower resistor at different switch positions.

 
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09-29-04, 04:31 PM   #4  
Tried to take some meter readings at resistor plug

The resistor plug has four electrical tabs. I found out which of the tabs always had about 14.11 volts with the switch in either position with the engine running. The full blower setting put out voltage on each of the three other tabs , which surprised me. On the tab next to the 14volt tab about .6 volts were recorded.The tab next to that about .4 volts were recorded and the last tab about .3 volts were recorded. I did this testing with the resistor plug unattached to the resistor.

When the blower was set to postion two and three (low and mid range setting) I didn't get any voltage (maybe .1 or .2) on any of the three tabs besides the full power tab.

Does this mean my rotary dial switch in the dash is bad? Can I just replace the switch do you think or do have to get the whole climate control module.

 
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10-06-04, 02:36 PM   #5  
This is getting expensive

I have now replaced the blower motor resistor and the dash board rotary dial switch.
I have checked continuity between the dash board switch and the resistor on all 4 wires. I still don't have low and medium speeds on my HVAC blower motor. Full blast works fine.
Concerning this issue,any ideas would be appreciated.

 
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10-06-04, 03:10 PM   #6  
Maybe you blew a fuse during testing,some vehicles have a hi blower and low blower fuses.I would actually check all fuses in the car sometimes you never know by how they are marked what they may affect.

 
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10-06-04, 03:57 PM   #7  
jeherrin
Funny thing.. I just ran into this in the spring. It was the blower relay switch. It drove me mad for weeks on this problem. The switch would only work on high and not on the slower speeds. I hope that you aren't working on a Dodge caravan because the damn relay was behind the power block under the dashboard. 2 hours later it was changed out and worked great.

 
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