403 Wiper Motor Tinkering - Diagnosis

[James Gelido]

Hi all,

Bit of a small issue but thought it would be worth a post for anyone having similar issues.

Recently took apart my 403 wiper motor (photos attached). The motor was gummed up and had all kinds of dirt and grease build up in her.

Proceeded to clean the gears and soaked the armatuer in fuel to loosen any particulars. Then, lightly sanded the the stack and commutator bar and used a razor blade to clear out the commutator slots/lines. Checked the commutator with a multimetre in lowest setting using these three methods https://www.youtube.com/watch?time_continue=56&v=qNV7TylIzSY&feature=emb_logo . Checks out fine.

Attached wiper motor to little 12v bench battery and magnet kicks in, metal pulls back, but armatuer does not spin. Bushes are okay and there is spark betweem them, checked all other points with multimetre and no shorts or loose connections. It is almost as if armatuer is jammed. Looks like it wants to move but something is jamming it. I did have it going 2 times after manually spinning the armatuer then connecting power, it spun as normal but then, nothing. Sometimes shutters as if it wants to move, does a little 3rd of a spin then stops. Now, nothing at all. Just a click when the electro magnet activates.

Any ideas on how I can overcome this or am I just wasting my time and should source another motor?

It's just such a nice piece of machinery and would be great to preserve it, would be sad to let it go to waste.

Cheers,

James

 

[Peter C]

This may be no help at all as it could have nothing to do with your problem.

I'm not sure that I would've used fuel to clean the armature windings. Some advocate using water, and I wouldn't use that either. Whatever is used, (brake cleaner?) it must not react with the copper wire insulation or leave a residue. Water would also seem to be a bad idea as it could leave moisture behind which could eventually cause insulation to break down and cause a short between the windings.

Have you checked the resistance of field coil? Are you sure the armature isn't binding mechanically?

 

[Kenfuego]

Having cleaned a few over the years, the most likely problem is that the carbon brushes are not contacting the armature. That would be my first re-examination, can be a variety of reasons, some mentioned. Good luck.

Ken

 

[James Gelido]

Having cleaned a few over the years, the most likely problem is that the carbon brushes are not contacting the armature. That would be my first re-examination, can be a variety of reasons, some mentioned. Good luck.

Ken

Hi Ken,

Bushes seem to have plenty of contact, after a bit of experimenting, actually found if I slightly pull the brushes away from the armatuer, it generates a better spark and some (very little) movement.

 

[James Gelido]

This may be no help at all as it could have nothing to do with your problem.

I'm not sure that I would've used fuel to clean the armature windings. Some advocate using water, and I wouldn't use that either. Whatever is used, (brake cleaner?) it must not react with the copper wire insulation or leave a residue. Water would also seem to be a bad idea as it could leave moisture behind which could eventually cause insulation to break down and cause a short between the windings.

Have you checked the resistance of field coil? Are you sure the armature isn't binding mechanically?

Good point. Someone did suggest to use fuel as we had used this to clean the starter motor armature and it seemed to work. I guess this is a much more fragile motor and armature. Will keep this in mind for any future work. Would you suggest electrical contact cleaner? (usually by motortech)

Coil resistance seems to be okay. When I press the magnetised bit of the claw, that holds the armature, and with my other hand, spin the armature manually, it spins freely with ease.

 

[Andrew Watkins]

What about the gear train?

In doing an identical 6V one I found that one has to get the gears meshed properly and stable or it jams intermittently

Andrew

 

[Peter C]

Not sure what to use but it needs to be something that evaporates completely and doesn't attack the wires insulation. That's why I wondered about brake cleaner. Other more knowledgeable people might know for sure. If possible, I would try a different armature.

 

[Kenfuego]

Hi Ken,

Bushes seem to have plenty of contact, after a bit of experimenting, actually found if I slightly pull the brushes away from the armatuer, it generates a better spark and some (very little) movement.

View attachment 119148

Sparking is like arc welding, those seem more modern than the old carbon brushes and it takes a while to bed those down in close wiping contact, they look too hard to bed in quickly and transfer power to the stator without arcing. Typical of problematical modern materials, but very simple (if it works o.k.)

Not the materials that I am used to finding. leave that to others familiar with those materials.

ken

 

[PCOATES505]

are you trying to run it without the cover on? these rely on a nylon piece in the cover to centralise the armature and stop it from jamming on the magnets.

cheers Pete

 

[James Gelido]

are you trying to run it without the cover on? these rely on a nylon piece in the cover to centralise the armature and stop it from jamming on the magnets.

cheers Pete

I was, yes, and this makes sense. As the armatuer would shutter, like it wanted to move and did spin sometimes.

Unfortunately, now, it doesn't even do that. Thinking I may have damaged the armatuer wires insulation trying to clean it with fuel. That being said, I cleaned the starter and generator armatuers with the same method and seemed to get them going, but, the wiper seems much more delicate.

Did you have a photo of the nylon bit? Seem to be missing it in my motor.

Thanks Pete

 

[PCOATES505]

the cover

 

[peugeotnut]

it would be better to search a later 404 or early 504 motor that has a cut off within the motor itself. the single wired motor tends to stop all over the screen depending on the shunt switch that's located under the glove compartment. the mounting motor plate is a little wider too for the built in shunt motors.

I was, yes, and this makes sense. As the armatuer would shutter, like it wanted to move and did spin sometimes.

Unfortunately, now, it doesn't even do that. Thinking I may have damaged the armatuer wires insulation trying to clean it with fuel. That being said, I cleaned the starter and generator armatuers with the same method and seemed to get them going, but, the wiper seems much more delicate.

Did you have a photo of the nylon bit? Seem to be missing it in my motor.

Thanks Pete