Hi guys, this is my first post. I have a 2007 Accord 4-dr sedan (LX maybe?) no climate control.

The air stopped blowing on all speeds last week for no apparent reason. No air will come out of the vents on any settings. When I turn the ignition on and then the fan on, the A/C compressor (I think) will run for 3 seconds and then turn off. This only happens when I turn the fan on for the first time after turning the ignition to on.

I have checked all fuses and relays (all good). I bought and installed a new transistor before testing the old one, which didn't fix the issue. I then tested both the old and new blower motor transistors (both good). I jumped the blower motor itself, and it ran fine out of the car. I am lost as to what the issue could be...

My next plan is to run the HVAC diagnostics test to see if it gives me a code. (I will update how that turns out).

The only other idea I have is to replace the entire control panel unit. I took the radio/display/A/C control panel out of my car already to see if any cords had come unplugged. All looked well.

I'm asking you guys for any advice on what to test next or any possible solutions to this issue. Also, is it a good idea to buy a new control panel to replace mine to see if this fixes the issue? Thanks for the help!

 

I don't have a circuit drawing for that car, but suggest you also check for flaky ground connections in that blower circuit.

Check fuses by measuring continuity? Or did you just check them visually? I've seen threads where the end result is a fuse that "appears" to be good but when tested it's open-circuit.

 

I ran the HVAC DTC test and got a 6 which I read means there is a problem in the blower motor circuit. Any ideas on what could cause this or any solutions to this?

Regarding the fuses, I only visually checked them. Going to have to go borrow the neighbors multimeter to check for continuity... correct?

 

1. Check/Re-Check the following fuses:

• Under-dash Fuse No. 30 (7.5A)
• Under-hood Fuse No. 21 (40A)

2. If fuses are/look good, check for voltage on both sides of the aforementioned fuses.

Under-dash fuse No. 30 will only have power with the ignition in the ON position.

3. If there is power on both sides of those fuses, then check the voltage at the Wht/Blu wire that connects to the blower motor. (You can also just check voltage at the Wht/Blu wire with the ignition ON as the first step. But if no power, then start with the other steps of checking fuses).

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4. If there is power at the Wht/Blu wire with the ignition ON, then the issue is probably on the ground side (e.g., wiring, power transistor, or HVAC module). With a spare piece of wire, insert one end into the Blk wire terminal of the blower motor connector and plug it back into the motor. With the other end of the spare wire, touch to the car's metal (unpainted) - ground. With the ignition ON, does the motor run?

 

You can try unplugging the connection to the blower motor under the dash and verify the white/blue wire has 12V when the key is in the II position using a volt meter.

The other quick test is to swap the blower motor relay with an identical relay nearby. The blower motor relay is in the under hood fuse box.

 

Redbull or PA, do either of you have a manual showing the ground locations for him to check? Seems like a 10-year-old car, a flaky or loose ground wire isn't out of the question.

Redbull's check #4 will narrow it down to a bad ground, but I'm just thinking of where the ground wire is screwed into the body.

 

The ground is G503 (located behind the glove compartment). The ground wire goes through Junction Connector C404 (left side of dash); and then branches out via Connector C404 to various other wires to provide ground to the blower motor power transistor and other components circuits.

 

My guess, test to be sure, is the blower resistor has gone. Test it out, if bad be sure to get one that fits the car - 2 door is different than a 4 door and some sites/places are not clear on this. I replaced one a few months ago on my 07 Accord, I got it from the dealer for less than $85.