Blower Fan Stopped when Wife Hit a Bump

[mweiss]

So now they are telling me that the blower they sent is an original Motorcraft made by Brose. If it's original, then why was it not moving as much air as the original, when it did work for the first month?

 

[koda2000]

RockAuto shows a 24 month warranty on the Motorcraft blower motor (assuming that's what it is).

 

[mweiss]

Well that's what they claim.. Brose = Motorcaft.. Sure didn't move air like the original. But maybe it was defective from the start.. hypothesis: one winding open, motor lacking power. Last shut off stopped motor at dead winding and won't restart. That's my hunch.

 

[mweiss]

So Rock Auto closed my ticket and isn't receiving anymore e-mails.

I wrote the following:

"I took the motor out this afternoon. When I tested it, it worked. So I put it back in. And it worked. Once. The next time I turned it on, nothing. Dead.

So I took the motor out again and tested it with an ohmmeter, while rotating the shaft. Most of the rotation reads 2.3 ohms. But there's one spot where it reads over 50 ohms. The motor has a dead spot in the commutator.

I am returning it."

 

[J_C]

Rock Auto is starting to annoy me too. More than once I've received items other than pictured or pictured under some cheaper brand. I accept that there are fewer manufacturers than brands so two or more companies might sell the exact same thing, but all of us expect to receive a top shelf part when we're willing to pay for it.

 

[mweiss]

It's all boxed up and waiting for Fedex to pick up Thursday. Meanwhile, my truck is disassembled and undrivable. Figures we'd have a holiday right smack in the middle of this, the hottest week of the year so far.

Obtaining good parts for these older trucks is really starting to be a problem. My wife keeps saying to sell this truck, but I don't want anymore debt/auto loans.

 

[koda2000]

@mweiss I just noticed you live in New Milford CT. I lived there from '82-'93, before I got transferred to Atlanta. Nice little town. One of our favorite things to do in the Fall was to attend the Bridgewater Fair. Ever been?

 

[mweiss]

Been to the BW Fair once.. recorded a concert for a band called Whitewood.
Taxes are killing us here. Since 2015, we're working on plans to relocate to Japan. Much better standard of living, less intrusive government and food there doesn't make me ill all the time.

 

[mweiss]

Update on that blower from Rock Auto... it's dead again. Probably less than 3 hours total run time over the year. It went out on my last summer. I was driving the vehicle 1-2 times per month, so not a heavy use vehicle.
So now I need to seek out yet another blower, maybe go with an original rebuild is better? The new blower never worked as strong as the original one, "HIGH" would blow about as much air as "LOW" on the old blower.

 

[CDW6212R]

Have you ever replaced the blower resistor unit, which is in the outside housing? That is a weaker link than the motor itself, those often have issues with the terminals or wires, due to the long term high current. I'd first remove that and look closely at it, before concluding the motor is the problem. If the fan stops in a short time like months or a couple of years after being new, I'd bet the motor wasn't the cause unless if it is a good brand.

 

[J_C]

That does seem like a very short lifespan in running-hours. I agree with CDW that more investigation could be useful, including the fuse, relay, and speed switch.

That blower resistor, normally the blower would still work on high, but you can just jumper between two (of the 4) wires going to it, to complete the circuit for the fan. I "think" (maybe) the two wires to jumper are on the opposite ends of the connector, orange/black and red/orange wires.

Also on the resistor assembly there is a resettable thermal fuse, and with age they can fail, or in some cases when they trip, they won't reset until power to it is turned off... it's bullet shaped and will read low resistance with a multimeter if working and reset, though with tarnish on it you might need to clean off an area to get a valid multimeter reading.

If you end up committed to buying a replacement blower, one last thing I'd do is autopsy the old blower first. Maybe it can't easily be opened, might need spot welds drilled out or something, but if it turns out to be easily repairable, might be able to bolt it back together. Examine bearings, brushes, commutator. When they get very old it is common for the bearing, or really I mean bushing to dry out but it shouldn't have happened in this short a period unless the factory skipped the step of loading it with oil. Regardless if it has resistance turning, either something very bad happened to the brushes or the bushings just need cleaned out and oiled. There are other things that can lock it up like core laminations flying apart but it's far less common. You can power it on a bench with a cordless tool battery if nothing else, the few volts higher won't make much difference for a short period of testing.

If it turns out that the thermal fuse in the blower resistor has failed, could be overheating from partial airflow blockage and time to check air passages and make sure there isn't a clog from leaves, seeds, or some critter nesting in there.

Wiring diagram attached. If I've got it wrong and you have the automatic EATC version, get the full pack of wiring diagrams in my sig and look for the one with EATC in the name.

 

[Jason94sport]

I have yet to track down why I have no 2-3 fan speeds. tried 3 sensors, the switch, no vacuum leaks. Works on 1 or 4. I downloaded your wiring diagram.

 

[J_C]

^ Since high speed goes straight to the fan through the switch and low has to go through the entire resistor series, odds are that your speed switch is faulty, or the wiring or connectors between it and the resistor module. I haven't taken apart a speed selector switch but it might be possible to do so and polish up the contacts, or try contact cleaner without disassembly if it's not complete sealed shut.

Then again you can check contact pole to pole switch resistance with a multimeter, or a replacement switch if needed is only ~$12 on Amazon or Rock Auto.

It's not vac related.