1998 Accord w/ manual HVAC

I realize this is probably a moot question, but I’m more curious than anything.

I’m working on repairing the mode door actuator because the Honda replacement is about $400 and I’m not finding any reputable replacements from the aftermarket.

I’m confident the issue was worn contacts between the motor and internal circuits, but just out of curiosity, I decided to check the current draw on the motor directly while I have it apart.

I found the current draw in one direction was +/- 60 mA and the current draw in the other was +/- 80 mA.

So I just wondered if anyone else has actually bothered to check the draw and what it was.

Thanks.

 

I never checked the amp draw on those motors. Assuming the motor has constant battery voltage @12.6V, then a 0.6-0.8 amp draw would be 15-20 ohm resistance in that circuit. You could cross check with the resistance measurement on the motor.

I've seen some youtube video on how to take apart the door actuator motor and do some cleaning for good contacts and greasing of the gears. I bought a used blend actuator and found my motor was the issue. Swapping in the used small electric motor fixed my issue. Since your's is not working, it is worth a shot.

 

I’m in the process of studying & self-teaching electronics repair to help further my career (I’ve been a practicing tech since 2016). This actuator is my first attempt at a legitimate repair that will benefit a customer (though I’m waiting to inform the customer until I know if it’s a successful repair or not).

The original issue was that it would move one direction and then MAYBE back the other way once, but then it was done and wouldn’t move anymore until it had several hours to cool down. I found evidence of fretting on the terminal contacts so I’m certain at this point they just needed to be cleaned, but I’m also going to solder the motor terminals to the copper in the housing to prevent that from happening.

I measured resistance between the motor terminals directly and got 35.0 ohms - not too surprising considering it’s 26 years old and has served in a midwestern US climate for that time.

I used 13.5 volts for the calculation because its normal use is with the engine running and alternator output will increase with the HVAC on - especially at idle.

I = V/R = math, or so I’m told.

0.386 = 13.5/35.0

So I’m getting 2 - 2.1 times the theoretical draw - but again, not too surprising given its age and history.

I’ve been documenting everything which will hopefully make it to these boards by the end of the month (with pics) which is another reason for asking about the typical current draw. I’m just getting into this level of repair so I’m trying to remind myself and keep track of the basics.

I’m gonna try some electronic contact cleaner on the motor - so far I’ve just given it some shots of compressed air without any cleaner.

I considered purchasing an off-brand actuator (cheapest I could find on Amazon was $31) just to compare the current draw (and possibly swap the motor over) but I’m not in a hurry about that.

Thanks for the response.

 

Well, it looks like I’m gonna have to replace the motor.

I got it reassembled, soldered the motor terminals and tested it - first full sweep no problem, then it quit in the middle of the 2nd full sweep, so the motor must be internally worn as well (again, not surprising).

I found a couple of promising replacements on Amazon that I should have by Wednesday, so I’ll see which one matches best and go from there.

 

I’m going to be posting a write up about this repair “soon” (relative to the age of the earth ) but I just wanted to conclude this thread by showing that the reason why the motor only worked once or twice is because the brushes were no longer there.


Arrows show where the brushes should be. The “blocks” on the other side of the contacts are foam - not sure if they were meant to be insulators or vibration dampers.