Blower motor troubles

[_JohnnyD_]

Today I was doing some wiring and I turn on the blower motor on for the first time on a few years on my project car. The motor works great on speed 4. No problem I had a new resistor pack, so I through it in and then the motor worked on speed 3 and 4. After running for a few minutes, the motor would work on speed 2 although it sounded like it was struggling. I couldn't get it to turn on in speed 1 at all.

I'm pretty sure my blower motor has some bad brushes or a seized up bearing so I will need to get another one.

Is there a way to diagnose a used blower motor to see if it is any good or should I just buy brand new? My motor looks and sounds perfect with direct 12V (or speed 4).

[SmokeE30]

I would reccomed either buying a new one or a known good working used one, taking a chance on a junkyard blower motor isn't worth it to me because as you said yours seems to work with a bench test but obviously has an issue in the car

[jlevie]

I would not bother with a used motor. Just get a new one.

[_JohnnyD_]

Is there anyway to measure the resistance across the motor to deterimine if it is still good?

[jlevie]

A resistance check will tell if the motor is shorted or open, but not much else. The brushes could be worn, the commutator iffy, or the bearings bad. You can roll the dice with a used blower motor, but don't bother if there is any damage or cracks in squirrel cages, or skip the frustration by buying a new motor.

[FLG]

They sell new brushes on ebay...might be worth a shot?

Mine just crapped out as well, sounds similar to yours. Works on 4,3,2 (struggling) for about 10 min then finally just comes to a halt or just barely is moving.

Id love to buy a new one but they are around 250$!!

[dashboardmonkey]

I say buy a new one. Depending on who you go through to buy will determine price. I got a new behr heater fan for 150 iirc from my guy. He gives me parts at cost +5%. He is a euro guy that deals in mostly vw stuff but gets bmw parts from the same warehouse. I always get parts from him, good prices and excellent customer service.

[reelizmpro]

Why so quick to order new parts? The motor has been sitting for years. At this point remove the resistor board and spray the motor contacts and brushes with contact cleaner and wd40 for lubrication. Reinstall the resistor board and test. There's a very good chance it will now work on all speeds. If its intermitent, then replace the brushes or entire motor.

[dnguyen1963]

Why so quick to order new parts? The motor has been sitting for years. At this point remove the resistor board and spray the motor contacts and brushes with contact cleaner and wd40 for lubrication. Reinstall the resistor board and test. There's a very good chance it will now work on all speeds. If its intermitent, then replace the brushes or entire motor.

OP said that he had a new resistor pack...I assumed he had done what you are suggesting already.

[Quinthirty]

Just to verify the info, as I also experienced my blower fail before I pulled out of the garage. Speeds 1 to 3 not working, only 4. Saw the diagram that speed 4 is a direct connection to switch and bypasses the resistor. I suppose I have a busted resistor, or has anyone experienced just cleaning it, and putting it back in?

How does one know if the safety switch went on, and if it did, how do you put it back to "normal," if that's even possible.

Thanks in advance.

[Quinthirty]

Safety switch indeed went on, and for some reason it reset itself before I started to work on it, and so the blower is working in all speeds again.