Broken headlight motor

[Alex(Tenerife)]

When my headlights stopped behaving as they should I thought oh no I hope I don't have to replace the diodes again. So after much checking of them in the car I finally gave in and removed the motor and checked the diodes. They are fine. So time to start digging further.
I couldn't find any reference of anyone cleaning up the motors themselves online so I took a brave pill and started undoing screws.

When I pulled the motor apart I think I broke the plastic holding the bush in. oops. Luckily I was able to glue it back together. Seems to be holding so far and in normal operation there shouldn't be any force on the joint, its more there for assembly as far as I can see.

The actual problem seems to have been a big blob of grease on the end of one of the bushes. Now its cleaned up I get a good connection from the bush to the central pin on the back.
I also while I am taking things apart cleaned up and replaced the grease on the worm drive, I also took the shaft out, gave that a clean and a sand with fine emery paper, degreased and reinstalled.

There is a cam on the gear wheel that opens and closes contacts, presumably to stop the motor at the correct point.

This pic is before I cleaned and replaced the grease. I cleaned up the contacts and this is when I noticed that at rest one of the contacts is closed and the other is not quite closed.



This one is closed

This one is still open

Before I put it all back together for a final reassembly, should this contact be encouraged to be closed when at rest?

btw if you do this there is a gasket to replace, so be ready for that. Also on the shaft with the splines, there is a collection of washers and an o ring. I cleaned these up and re-used. For final re-assembly I may use a new o-ring.


Hope these pics help anyone else who needs to do this. On disassembly you will need to poke something in there to retract the bushes. You might be able to prise off the retaining clips before you remove the motor body, but that could be tricky. Something to consider for next time so I don't break it. (I hope not to have to do this again)

 

[Alex(Tenerife)]

Reassembly of the motor was done with the aid of my darling wife. We held back the bushes with thin invisible thread while the shaft was pushed in.

During this process I discovered a small plastic bush? holder type thing that the shaft needs to go into.

Cleaned up the earth connections and the motor spins.

But I think that connector I mentioned above is an issue as it only half works

 

[ng_randolph]

This one is still open
View attachment 81237

Hard to tell from a photo, but for the contact that doesn't quite close, it looks like the stationary tab is slightly bent.

 

[Dr.Jeff]

Hard to tell from the pic but that failed brush holder (yellow arrows, below) almost looks melted more than broke. Excessive electrical resistance may have overheated it, causing it to melt and the brush to fall out. That may have been the reason for the motor failure in the first place?

 

[Alex(Tenerife)]

Hard to tell from the pic but that failed brush holder (yellow arrows, below) almost looks melted more than broke. Excessive electrical resistance may have overheated it, causing it to melt and the brush to fall out. That may have been the reason for the motor failure in the first place?
View attachment 81250

I think that is just an artefact of my cheap phone camera. In real life those marks are not there.

 

[Alex(Tenerife)]

Hard to tell from a photo, but for the contact that doesn't quite close, it looks like the stationary tab is slightly bent.

So this was a problem. The stationary tab was bent out of place and the arm also needed some adjusting. So bit of an adjust and a clean and the contact was good at rest.

So took me 3 attempts to make a new gasket, first time I cut my own from sheet gasket. Found a new o ring in an old scuba regulator service kit (they always come with more than you need). Reassembled. Cleaned and tested good.

Reinstalled and headlights work great. If anything the other side could use a little service as well as its a little slower but overall working well.

Hope this helps someone else, I have more pics that I posted, so if you find you need further pics to understand how these work, pm and I will see what I can find.