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My A/c is cold, but the fan when pressing max ac doesn't seem to roar anymore, the fan doesn't seem powerful. The manual controls also do not seem to make the fan powerful. Maximum blast seems like low speed.
Replaced the cabin filter which was nasty and the air seems cleaner now and still cold but no power pushing the air. Also I did the AC reset button defrost/recirc, reboot but that didn't seem to do anything.
I have an ac/heater blower motor I plan to install but are there any other things to try out?
I used my code reader and went into the SAM air conditioner section and it doesn't have any faults. I don't know what to check for in the live data to see if something is telling without an error.
Advice on what to look for in the live data?
2010 e550 sedan
Last edited by Boarderjosh10; 08-18-2023 at 03:48 PM.
My A/c is cold, but the fan when pressing max ac doesn't seem to roar anymore, the fan doesn't seem powerful. The manual controls also do not seem to make the fan powerful. Maximum blast seems like low speed.
Replaced the cabin filter which was nasty and the air seems cleaner now and still cold but no power pushing the air. Also I did the AC reset button defrost/recirc, reboot but that didn't seem to do anything.
I have an ac/heater blower motor I plan to install but are there any other things to try out?
I used my code reader and went into the SAM air conditioner section and it doesn't have any faults. I don't know what to check for in the live data to see if something is telling without an error.
Advice on what to look for in the live data?
2010 e550 sedan
I would remove the dash bottom cover on the passenger side, and with the AC on verify visually the blower is changing speeds as you press the speed fan switch on the AC panel. Using the scanner live data you should be able to see the percentage of AC blower actuation, or the voltage at the blower motor . At max speed it should be near peak of the alternator, ie. @14V. If nothing happens when you switch from low to high, you may need to measure voltage on the blower connector to verify how the voltage changes as you go low<->high. If the voltage is there but blower seems at constant speed, the resistor is GONE.
Thank you!!
I checked voltage of the AC blower motor and it gets to 11v when the AC is on max and seems to step down by a few volts as I lower the fan speed to low. I replaced the blower fan motor and it's giving the about the same voltages. The old blower motor requires more effort to spein it manually than the new one so it was probably time to replace.
What should I try next since the fan speeds are still not that powerful?
is the resistor part of the blower motor?
I have never taken mine out, so I do not know where it is located, but it must be close by.
Certainly, you should be able to check the resistance between the different inputs to determine if they are up to specs. Not familiar with their failure points. You mentioned the old motor has more friction to spin and that can cause a higher load to move it --> burn the regulator? Also, you tested with the car OFF, correct? 11V sounds about right with the car OFF. Otherwise, there is seems to be a voltage drop of @3V from ALT voltage, a bad ground around the passenger footwell?
If you determine is the regulator, and feel adventurous see someone working on the resistor of a Honda Odyssey. Likely ours is sealed to prevent DIY fixes, but if you buy one new, please take the resistance specifications before installation and post them here. It would help in the future
You have a new blower with clean filter but fan speeds still slow...
This controller module is built with good quality. It acts as what old resistors used to do to control speed but with DC pulses for better efficiency. I don't think it's directly a top suspect...
> CHECK the GND circuit!
The blower is a high-power circuit that requires good connections to pass tall current spikes.
> Experiment blower motor:
The new fan may not be too compatible with pulsed control. Try oiling shaft bearing and reinstalling it for comparison.
> Open inspection:
Have a look if you want... power path
FIXED!!!! Got the regulator/resistor thing that looks like a bunch of metal rods sticking out. Right between the cabin filter and blower motor. Now the AC works great, almost too good as I can hear the fan spinning more than the past one but the power I was hoping for is there now.
Onto the next few items to figure out.... Thanks so much!!
FIXED!!!! Got the regulator/resistor thing that looks like a bunch of metal rods sticking out. Right between the cabin filter and blower motor.
Now the AC works great, almost too good as I can hear the fan spinning more than the past one but the power I was hoping for is there now.
Onto the next few items to figure out.... Thanks so much!!
yes, the fan controller with all the "metal rods sticking out" is the prior style ballast. It has a lot of heat to dissipate so it needs good AIR FLOW through the filter and blower bearings not ultra dry to force high currents. hot fins need cooling
Usually a thermo-fuse on the circuit board blows up to require swap unless you bypass fuse to get HVAC going.
Anything for science!
I could see how a clogged filter could cause over heating. My air filter was disappointingly dirty and I had a a very dusty couple of years in Arizona. Noticed the failure within 30 days of moving to Washington with a more humid climate. Wondering if it caused the dust to solidify more and then....
pretty sure the metal piece is not supposed to be rainbow
Last edited by Boarderjosh10; 08-18-2023 at 05:12 PM.
So it is not resistor that porcupine thingy. Its a pulsing power supply, almost like a PWM too yah Cali ?
The way this unit has such a large heatsink compared to "facelifts" makes me think the transistor is just delivering a DC voltage from 0 to Max, not pulsed.
At 10V the transistor is dropping 4.5V under 20Amps... that's about a 100W heat that needs to escape.
The difference with PWM is the conduction mode of transistor. It hardly has a drop voltage to create heat because transistor is either on or off, not switching in-between according to slew-rate specs (ultra-fast switching).
The low heat is caused by the small internal resistance.
Either way you want...
lubed up shaft bearings for minimal current and
a clean filter for air flow.
Replaced the cabin filter which was nasty and the air seems cleaner now and still cold but no power pushing the air.
2010 e550 sedan
Originally Posted by CaliBenzDriver
Either way you want...
lubed up shaft bearings for minimal current and
a clean filter for air flow.
The blower was overworked, and age -> dry lubrication if any --> high A --> Booom!! --> New Regulator after some frustration.
I am due for an air filter check , lubing the blower, replacing the "pre-filter" -> dryer sheets under the hood, and engine air filter --> Saturday morning booked for . If the weather is nice I may take a stab at the throttle body.
I am due for an air filter check , lubing the blower, replacing the "pre-filter" -> dryer sheets under the hood, and engine air filter --> Saturday morning booked for . If the weather is nice I may take a stab at the throttle body.
08-17-2023, 11:04 AM
