Blower motor stuck on?

JOHNSON SMITH

MEMBER
2008 SUZUKI FORENZA
2.0L
4 CYL
2WD
AUTOMATIC
140,000 MILES

Blower motor is stuck on whether the car is on or off. Before, 1, 2, and 3 speed setting would work but 4 would turn the blower off, now, it's just stuck on non-stop. I unplugged the relays and fuses and it's still stuck on, tried to unplug the resistor just to see what would happen, still on.
The only thing that stops it is if I unplug it directly and I don't understand why it's stuck on, the blower motor is brand new, but the resistor is OEM. Open to suggestions, anything helps thanks.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

The idea that high speed would turn it off in a way makes sense. That could supply power directly to the motor from fuse 7 in the interior fuse box if the switch itself was failing. However, it would have only happened with the key on.

Ugh! LOL You got a good one here. Do me a favor. I need two specific fuses removed to see if the fan turns off. Fuse 3 in the under-hood fuse box. Remove it and see if that turns the fan motor off. If it doesn't, remove fuse 7 from the interior fuse box to see if that makes a difference.

I have a feeling the problem is with the switch itself. If fuse 7 shuts the fan motor, that is where I would start.

I attached two pics below of the schematic for this circuit. You can use it as a reference. I have wires highlighted that I was using to diagnose. If the two fuses I mentioned and the blower motor relay doesn't turn the fan off, we need to disconnect the resister first to see if it stops it, or if disconnecting the connector at the switch itself turns it off.

Let me know what you find. Also, please confirm you were removing the blower motor relay.

Take care,

Joe

See pics below (pic 3 shows the fuse 7 position under hood and pic 4 is the interior fuse box)

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Monday, February 20th, 2023 AT 7:58 PM

JOHNSON SMITH

MEMBER
2 POSTS

Ah, I didn't pull the correct relay, I mistook the A/C compressor for the relay, oops.
Removed the HVAC Blower 30A fuse, plugged the blower motor back in and it didn't turn on. To verify, I disconnected the blower motor, put the fuse back in and reconnected the motor and it turned on again. The interior fuse, however, had no effect on the blower motor.

If the switch itself is bad, how would I diagnose and go about fixing /replacing?

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Monday, February 20th, 2023 AT 9:07 PM

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

If the power turned off with the fuse removed, there is a good chance the relay itself has failed. If there is a different relay having the same part number, switch them to see if it works. If there isn't, here is a link that explains how to test the relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Let me know.

joe

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Tuesday, February 21st, 2023 AT 8:22 PM