Blower motor issues on '03 Sequoia

[atikovi]

Problem #1) Sometimes it works and sometimes it doesn't. I checked the wiring by wiggling and there was no change, and the connector was nice and tight. No corrosion on the terminals and 12 volts and ground on the connector when set to full speed. If I bang on the motor, it comes to life. Assuming something internal is loose. Any chance of taking it apart and fixing that? New no-name one is $40 delivered, but if I can fix it NOW, that would be better.

Problem #2) The airflow out of the vents is pretty weak even on high. This has the electronic controller. Does this system use electric blend doors that may be stuck half way? Or after 500,000 miles, is the motor likely just worn out?

 

[Rand]

Is there a cabin air filter? check airflow with it out.
if motor isnt working right.. check airflow after its fixed.
any chance that uses a resistor board for speeds?

blend door is easy to check put it on vent and see where air comes out, put it on floor etc.. also check hot and cold.
note some cars dont operate exactly as you would think.. I had one that would put some air out the defroster on all settings.. and it was designed that way.

 

[atikovi]

No cabin filter. I'll check those for function.

 

[Dave9]

If banging on the motor makes it work, there's little point in checking anything else until you get the motor working properly.

Odds are it's one of 3 things, dried up bushing/bearings, bad spot on commutator, or worn out brushes. At this point there's no loss trying to disassemble it to see what's going on, though if the squirrel cage is turning stiffly by hand you could try to lube it except that the back bearing is probably sealed so the end cap has to come off.

If it's welded together, might not be so easy to put back together if salvageable, but bent tabs can be bent both ways (carefully) or spot welds joining two flat panels, drilled out and then fasten back together with bolts, and same for rivets... maybe, hard to speculate without seeing it.

Bad spot on commutator might be cleaned up with fine sandpaper, brushes might be replaceable, though a commutator connected winding could've come loose and degraded it too badly to salvage. Many people would just buy a new motor. I assume there's not a ton of debris built up that makes it hard for it to spin, I mean in the squirrel cage cavity not motor itself.

 

[zzyzzx]

At this point, you have nothing to use by disassembling the motor, so give it a try and post pics. It would check the brushes. If that's the case then you can buy generic aftermarket brushes (you might need to modify them). If you end up doing this post pics of the work.

 

[atikovi]

I found a TYC motor on Amazon for only $36 delivered that should be here tomorrow. Even if the brushes can be replaced, the bearings must be worn too as it's making some noise as well.

 

[zzyzzx]

OK, now that the old one is trash, will you do a disassembly and diagnosis on it?

 

[atikovi]

After I get it out I'll take a look.

 

[meep]

I’ve seen these fail as soon as 60k miles or so. Last one was a Chrysler. it finally failed from worn brushes, but leading up to it, it began pulling more power as indicated by the mechanical volt meter than showed a dipping pulse in the needle when the fan was on, and it acted like a short and wouldn’t spin on the lowest speeds. Commutator was likely junked up and shorting, and the brushes wore. No need for post mortem, I also replaced with a tyc. Note, my tyc had a whine to it which was super annoying on speeds 1 and 2 of 4. You might try to bench test yours before installing. The whine was no fun.

 

[Nick1994]

With all those miles and no cabin air filter, the evaporator or heater core could be plugged with dust, dirt, and debris restricting airflow.

 

[wrcsixeight]

Ive had the brushes get stuck twice, in a young VDO blower motor.

The second time I opened it, I made the brushes alightly smaller, to be looser in the holders, with 800 grit sandpaper.

Reassembly required holding brushes against springs with fishing line.

The tangs holding it together, will likely shear off the next time they are bent.

Once, since that second reassembly, i had to give it a light hammer tap, but no issues in the year since.

My vdos wires, red was the ground.
When it spun backwards, theree was still some air movement from vents.

Ive read about others having to swap the wires on new replacement blower motors. Was not a huge deal in my case, but could be a tool throwing curse fest in a different vehicle.

Might try and check which way it spins before commiting to the wire splicing, and not just assume the red or yellow wire is +.

 

[atikovi]

Here you go. Commutator rather dirty.

 

[meep]

yeah that looks pretty tired. Looks like there is pitting and abrasion. I’ve seen worse, but this one looks to have lived a full life.

 

[CR94]

Here you go. Commutator rather dirty.

How do the brushes look? Excessive arcing due to worn brushes will damage the commutator surface.

 

[atikovi]

Look ok to me but didn't take it apart.

 

[CR94]

This being a DC motor in a high-mileage vehicle, one brush likely wore to its limit.