A drumming sound around the dash

OLAMI

MEMBER
2003 VOLVO XC90
6 CYL
TURBO
4WD
AUTOMATIC
150,000 MILES

I discovered my battery usually drop gradually, but don't know why. But the strange thing is whenever I connected the battery cable (+) (-) to the battery post, a sound came up immediately like a drumming sound under the dash, for about 60 seconds then I took my time to observe what it is, then I saw arms that wind up and remain there and sound for like another 5 second before stopped. When I put the key in ignition it sounds again and wind down. It happened anytime battery is connected in order to start the car, which I think is the cause of the battery drain, anyone solution here I will be grateful.

8 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

Based on your description, it sounds like one of the damper motors has failed. There are several of these under the dash which do several different things. However, all things are related to the HVAC system.

The damper doors are what determine airflow direction, fresh air intake, air temperature, and so on.

If you look at pic 1, it shows the different damper doors. Pic 2 is an example of one of the damper motors.

The motors have a small plastic gear in them, and the teeth can wear out or break. As a result, you hear a clicking/ticking sound as it tries to move.

Let me know if what you saw appears to be one of the things indicated below.

Take care,

Joe

See pics below.

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Sunday, November 7th, 2021 AT 10:00 PM

OLAMI

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6 POSTS

Thanks for your swift reply, but how do I know which particular damper motor that was the culprit, any step-by-step procedure with picture on how to troubleshoot it, will be most welcomed. More so can the motor failure cause and excessive battery spark when connecting battery cables? Because I do experience an excessive battery spark each time my battery cables are just connected.

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Tuesday, November 9th, 2021 AT 1:16 PM

OLAMI

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6 POSTS

Another experience is whenever my battery cables are just connected, a relay sound is heard activated on the CEM under the dash and when I checked it was, CMI21 and CMI22 and CMI16, is it normal for this relay's to make once battery is connected?

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Tuesday, November 9th, 2021 AT 1:26 PM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

As far as the actuators, the best thing to do is place your hand on one at a time and have a helper cause the noise. You should feel it in the motor.

Oftentimes, you can tell exactly which actuator is the issue. At that point, I normally remove and see if it responds when requested.

As far as the relays, that is normal when they receive power. Also, a small spark isn't uncommon. I would need to see how bad it is. Make sure when disconnecting the battery, disconnect and reconnect the negative terminal.

Let me know if this helps.

Joe

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Tuesday, November 9th, 2021 AT 6:42 PM

OLAMI

MEMBER
6 POSTS

Alright, thanks Jacob. When I'm chanced again to work on the car, I will do the check and video the battery spark as well. Below is the position of the actuator's but I'm having 5 of them, one closed to the front passenger door side, while one at the driver side. Picture 1 and 2 is the passenger door side own. Take a look.

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