I will try to upload pictures of the heater blower motor in my 1992 Volvo 960. It runs some of the time and is the culprit in my troubleshooting enterprise. Today I tried it outside of the enclosure a number of times. Sometimes it would start and run. Other times it would not.

A little push on the fan would get it to run if it did not react to the command from the dashboard controls.o

This tells me that it is probably dirty inside and might be salvageable if I can get it apart

The four points identified on the picture have two small flanges at each point. One flange has been spread and the other is probably just some kind of a marker to align everything. I am thinking that I could squeeze the spread flange together and then pull the end of the motor out so that I could clean up the commutator, etc., and check the brushes for wear.

Has anybody done this before? And does it work?

Has anybody done this before?

-> I've attempted repair, long time ago, rather unsuccessfully. Couldn't even open the tabs with pliers. In retrospec I think the motor needs to be put on a stable work surface (eg. workshop metal table) and hit the tabs with out with a punch. I bought a new motor instead.

Amarin.

We got it apart and found one of the magnets loose. But we could have caused that damage when we were opening the motor using a fair amount of force. Glued the magnet back on but the problem was still there when we plugged it in. And then the fan broke apart when we tried to remove it. It is seriously glued onto the end of the motor shaft.

I just took it apart again and the magnet had moved. My gluing job had been unsuccessful. So the problem could still lie with the magnet coming unstuck.

To rebuild the thing and get to the brushes one would have to destroy the plastic fan and replace it with another one. A better glue job could have been instructive. C'est la vie!

Dear muskox37,

Hope you're well. How many miles on the car? Is the blower motor factory-original or is it a replacement? If the former, a 27-year-old motor likely is at the end of its service life. If the latter, it is worth "going inside" only if: (a) the motor was replaced recently and (b) you can source replacement motor brushes and/or bearings.

While a Volvo replacement blower motor (#3537857) costs about $300 at a U.S.-based Volvo dealer, FCP Groton (www.fcpgroton.com) sells for $90, a Four Seasons blower motor, which is likely to be quite serviceable.

Hope this helps.

Yours faithfully,

Spook

Hi Spook,

Hopefully this message will show the motor.

muskox37

Dear muskox37,

Hope you're well. Bravo!!!!

Use some brake cleaner (on a rag) to clean the motor casing, where you will re-adhere the loose magnet. Also clean the magnet's surfaces with brake cleaner.

Then, use an epoxy (two-part) to re-adhere the magnet to the motor casing. Let it cure for a day and then re-install the bearing plate.

That should restore the motor to good operating condition, so long as the magnet segment didn't damage anything, while it was "loose". My guess is that it didn't.

Well done!

Yours faithfully,

Spook

Hi Spook,

Thanks for your information. I used alcohol instead of brake cleaner but otherwise I followed you instruction, using the epoxy you recommended.

Bending the 'keeper' tabs back in place could be a bit tricky but otherwise I expect everything to fall in place sometime today.

Will keep you updated as to progress.

muskox37

Dear muskox37,

Hope you're well. I use MEK (methylethylketone) to clean metal before applying sealants or adhesives. MEK removes old glues, paint, grease, dust, etc.

However, MEK is highly flammable and carcinogenic, so I use it sparingly. As most do not want to handle MEK (a chemical cousin of acetone), I think brake cleaner is a good way to remove grease, dust, etc.

To avoid hammering on the metal tabs, that secure the blower motor's end-plate, it might be possible to use a vise-grip pliers, with jaws that open to the extent needed. A standard vise-grip pliers doesn't open far enough. A "wide-mouth" vise grips can apply a lot of pressure slowly and so carefully.

A bench vise can do this, if its jaws will open far enough to accept the motor's casing. Turning the vise's handle should slowly force the end-plate's tabs inwards (towards the center), securing the end-plate to the casing.

Hope this helps.

Yours faithfully,

Spook

Hi Spook,

We did end up using a vice to fold the tabs back into place and it worked well.

BUT we did try to get the fan off, thinking we would like to have a look at the brushes. And in so doing we heard a cracking sound and this lead to our defeat.

When we ran the motor it acted as it had always done, working five or six times and then not working. So we had not found the snag. We probably broke the magnet loose ourselves trying to remove the back plate.

And then one of the plastic blades on the fan broke off. Not convinced, I ran it at position five and the whole fan destroyed itself, with plastic shrapnel flying everywhere. Happily, neither of us were injured but it was the end for the motor. My partner thinks the motor has a 'flat spot' and that is why it works intermittently.

So I have ordered another motor in. A sensible person would have done it a week ago. Guess they are just not repairable. Regardless, thanks for your valuable input.

Don't win them all, it would seem.

muskox37

Dear muskox37

Hope you're well. Actually, you ascertained how to open and to re-close the motor casing.

I suspect the magnet came loose, because alcohol is not a sufficiently aggressive solvent. To get epoxies to adhere, surfaces should be surgically clean of all contaminants. Brake cleaner comes close. But nothng is as good as MEK for removing every trace of grease, paint, old adhesive, etc.

In any event, nothing ventured, nothing gained.

Hope new motor install goes smoothly.

Yours faithfully,

Spook

hi Spook,

I don't think the plastic fan can be removed from the motor without destroying it. Now that I have looked at it I think it was stuck onto the end of the motor during assembly with the idea that these things are not repairable. Knowing what I know now I might have tried to grind the end of the attaching plastic'capsule' to see if there would be any way of moving it.

I might have another look inside to see if the magnet broke loose again. I can't fix the motor but it would be good to know if the loose magnet was at fault.

I don't know why I did not use brake cleaner. I have some in the shop.

I will get back to you when I have installed the new motor.

muskox37

Hi Spook,

I will attempt to show what we think might be causing this blower motor to intermittently fail to start up when ordered to do so.

One of the motor magnets had come loose and moved around the interior of the motor housing about a quarter of an inch. It would seem to make sense that the motor would come to rest at various positions in its daily start and stop routines. Our guess is that when it stopped at this particular magnet, it would not start up again. Thus, started seven times, won`t on the eighth go around, etc.

I have two pictures and will attempt to upload them.

I got the end piece off by bending the four holding tabs outward.

Sensible people buy another motor and I am going to follow amarin`s lead to see if a motor for a Chevy Cavalier will fit, just in case I cannot refit the end to the motor.

But I am a retiree with time on my hands!

Some of the 700/900 cars used the same blower motor as a Chevy Cavalier? from around the same time frame. So purchasing as a Chevy was a lot less $$ than purchasing as a Volvo.

Read here and see if it applies to your car:

https://www.brickboard.com/FAQ/700-900/HeatingAirConditioning.htm#HeaterBlowerMotorReplacement

--
Current rides: 2018 Volvo S60 Inscription (What the heck do all these buttons do?), 2005 Volvo S80 2.5T (Soon to go bye-bye), 2003 Volvo V70 2.4NA (The family "truck"), 1973 Volvo 1800ES (STILL not road worthy!)

Sorry Chris,

I gave credit for your lead to amarin. Regardless, many thanks.

muskox37