Knocking in the blower motor

[5x10]

Ever since I replaced my motor relay, I have a knock coming from the blower motor

i thiught at first that I hadn’t mounted it right, but it’s mounted correctly
i can feel the knock in the plug coming off the side of the motor

anyone know what this is from?
im thinking it’s something in the motor itself

 

[Fless]

Moved you here since this is an Interior issue.

Remove the blower motor and check for blockage or miscellaneous material in the heater cavity. Then run the blower outside of the cavity to see if you can determine that it's coming from the motor. The blower cage might be out of balance.

 

[OR VietVet]

Yes, blower cage or something in there. Could be the armature hitting in there. You replaced the motor relay, why? How long had it all sat no working before the relay? Good to run it outside the housing for a close inspection.

 

[strutaeng]

Ever since I replaced my motor relay, I have a knock coming from the blower motor

i thiught at first that I hadn’t mounted it right, but it’s mounted correctly
i can feel the knock in the plug coming off the side of the motor

anyone know what this is from?
im thinking it’s something in the motor itself

Yes! I had this exact same issue on my 06 Suburban with the automatic control. Replaced the blower motor resistor (the only one that seemed to be a direct "plug and play" was from Amazon) and motor from RockAuto. I thought it was the motor, until I swapped another known good motor and same thumping sound! It sounds like something is loose or something like that.

I went back and the Amazon one and some reviews were saying this. I found a Four Seasons blower motor resistor that worked, I just had to cut off the old connector and splice the new one, but the instructions were very clear.

Problem solved!

I can provide part numbers if you want. The Amazon one was like $30-ish IIRC. No real name brand, made in China.

The Four Seasons was like $90 from RockAuto, assembled in the USA.

 

[5x10]

Yes! I had this exact same issue on my 06 Suburban with the automatic control. Replaced the blower motor resistor (the only one that seemed to be a direct "plug and play" was from Amazon) and motor from RockAuto. I thought it was the motor, until I swapped another known good motor and same thumping sound! It sounds like something is loose or something like that.

I went back and the Amazon one and some reviews were saying this. I found a Four Seasons blower motor resistor that worked, I just had to cut off the old connector and splice the new one, but the instructions were very clear.

Problem solved!

I can provide part numbers if you want. The Amazon one was like $30-ish IIRC. No real name brand, made in China.

The Four Seasons was like $90 from RockAuto, assembled in the USA.

Got it, I’ll try another resistor

ive taken the motor out of the mount and held it in my hand , and it still has the knocking, coming from the connector that attaches

it’s almost like the other side of the plug is interfering with the motor


edit, after some more research, the blower might be bad too, as the new resistor did Seem to open and even higher fan speed, but shortly after, went back to what I had been used to and didn’t have the higher speed

 

[5x10]

Got my blower/resistor kit in from rock auto
but

they are wired differently

my current resistor has a wiire coming to it and then a wire out of the resistor to the blower

rhe Replacement resistor only had a wire in, not one going out to motor
Not sure which one is stock

i need to get back under there and see if they clipped other wires(that led to the motor directly)

i did plug in the new motor and it seemed to have the same issue as my old motor, almost like it’s not a consistent Feed of power

 

[strutaeng]

My resistor was Four Seasons #JB2079. It had a black ground, red power and a purple wire. Those got spliced into the harness from under the dash, which had the same colors. Be careful with the red wire, because it's powered even with key off, and comes from one of the huge fuses under the hood fuseblock.

The motor connector goes into the resistor.

 

[5x10]

My resistor was Four Seasons #JB2079. It had a black ground, red power and a purple wire. Those got spliced into the harness from under the dash, which had the same colors. Be careful with the red wire, because it's powered even with key off, and comes from one of the huge fuses under the hood fuseblock.

The motor connector goes into the resistor.

Did yours have a wire coming from the resistor to the motor?

current

and replacement below

 

[strutaeng]

Did yours have a wire coming from the resistor to the motor?

current

and replacement below

Yes. Mine looked just like yours.

The new resistor actually has a female plug for the motor connector (I also had replaced the motor a few months ago with TYC 700164).

 

[5x10]

Yes. Mine looked just like yours.

The new resistor actually has a female plug for the motor connector (I also had replaced the motor a few months ago with TYC 700164).

Sorry, I’m a little slow

currently, harness to resistor, which then has a wire to motor

what’s the new order? I see a female port in the resistor(5 prong) and the blower motor (which has a 2npromg connection)

 

[strutaeng]

Sorry, I’m a little slow

currently, harness to resistor, which then has a wire to motor

what’s the new order? I see a female port in the resistor(5 prong) and the blower motor (which has a 2npromg connection)

Oh, I see. Sorry, I need to clarify: So my resistor came with wiring harness that plugged into longer connection. The black, red, and purple got spliced into the under dash harness (cut off the old connector). The other 2 wires coming out of the wide connector I think had a female plug there the blower motor connected. It came with clear instructions.

You resistor it sounds like didn't come with this harness? No instructions either? What resistor did you buy?