94 HVAC - Intermittent Blower (Easy Fix)
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Instructor
Joined: Oct 2008
Posts: 190
Likes: 4
From: Sonora CA
94 HVAC - Intermittent Blower (Easy Fix)
I've received some great help in this forum, so I thought I'd just add a little bit to the database on having a blower fan in the HVAC unit do the "sometimes on, sometimes off, sometimes just a bit" thing ...
I had that problem. It was really frustrating. I could hear the compressor engage, and there was cold air coming out of the vent. The problem was that the fan would not work all the time. Sometimes it would spring into action, but other times it would do nothing, regardless of the setting. So, on a hot day, the only way to get A/C into the car was to drive over 80 MPH (and then it would just flow in, without a fan). Received a nice big ticket in Sacramento, so I decided it was time to dig in.
First, did the remove the Head Unit and pencil eraser thing ... reinstalled it, and the buttons were certainly more responsive, but she was immediately back to her old tricks.
Second, replaced the blower motor. Things were good for a day or so, then she was up to her old tricks.
Third, replaced the Blower Resistor (also heard it described as the Blower Control Module, or BCM). Worked for a day or so, then back to her old tricks.
Fourth, took it to a shop, thinking the HVAC "programmer" was next in line. And, the guy from the shop called me, and said while he was checking out the BCM, his assistant (who was inside the car) noticed that the fan started working again. When he wiggled the pigtail connector to the BCM again, it went off. Wiggled it again, it went on.
So, we just replaced the connector, and IT WORKS GREAT.
Just thought I'd pass this along. If you are having a similar problem, I'd do "Fourth" above first. Might save some $ and headaches (not to mention traffic tickets
).
- WPK
I had that problem. It was really frustrating. I could hear the compressor engage, and there was cold air coming out of the vent. The problem was that the fan would not work all the time. Sometimes it would spring into action, but other times it would do nothing, regardless of the setting. So, on a hot day, the only way to get A/C into the car was to drive over 80 MPH (and then it would just flow in, without a fan). Received a nice big ticket in Sacramento, so I decided it was time to dig in.
First, did the remove the Head Unit and pencil eraser thing ... reinstalled it, and the buttons were certainly more responsive, but she was immediately back to her old tricks.
Second, replaced the blower motor. Things were good for a day or so, then she was up to her old tricks.
Third, replaced the Blower Resistor (also heard it described as the Blower Control Module, or BCM). Worked for a day or so, then back to her old tricks.
Fourth, took it to a shop, thinking the HVAC "programmer" was next in line. And, the guy from the shop called me, and said while he was checking out the BCM, his assistant (who was inside the car) noticed that the fan started working again. When he wiggled the pigtail connector to the BCM again, it went off. Wiggled it again, it went on.
So, we just replaced the connector, and IT WORKS GREAT.
Just thought I'd pass this along. If you are having a similar problem, I'd do "Fourth" above first. Might save some $ and headaches (not to mention traffic tickets
).- WPK
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You have a blower control module if you have the C68 digital HVAC system (the one with the temperature digital display).
The C60 manual HVAC system has a blower speed control resistor network and a high speed relay that bypasses the resistors.
I had intermittent fan speeds and found that the BCM connector was partially melted where the red wire from the starter solenoid goes into the connector. I replaced the connector shell and cleaned the pins on the BCM.
The C60 manual HVAC system has a blower speed control resistor network and a high speed relay that bypasses the resistors.
I had intermittent fan speeds and found that the BCM connector was partially melted where the red wire from the starter solenoid goes into the connector. I replaced the connector shell and cleaned the pins on the BCM.
Last edited by Cliff Harris; Apr 5, 2016 at 12:49 AM.
