Citroen C5 x7 wiper motor jamming fault

[darbuck]

Hi all, as you all know my C5 is a bundle of laughs, well it laughs at my tears at least.

Anyway I have two pairs of wiper motors and last week I had one functional motor. I was not buying another set and decided to have a go at fixing them. It turns out that the motors do actually jam.

I tried the magnet fix previously highlighted and it worked on one of them for a while but it stopped again not long after so I had another look . I found the shaft the magnet is on is actually a worm drive and binds on the cog inside the motor, I cleaned out the old grease which was kind of nasty and used screwdriver to rotate the shaft at the magnet to free it up and that seems to have fixed two of them.
so that gives me three functional motors My daughter's mate works in an electronics repair shop and she dropped the remaining PCB board in there for me this morning.
Diagnosis,Chips are swollen but not too bad and significant corrosion but they think they can fix it so fingers crossed I will have two functioning pairs by the weekend. I'll keep you posted.

[MattBLancs]

Sounds like multiple independent but related (due to water ingress!) faults being overcome there! Good work!

[darbuck]

Yeah I think so Matt, happy to have a win. I have the car a year the end of next month and still haven't driven it but the rack and a set of tyres on the back are the only thing left to do. Except of course the nest of spiders in the engine bay that I inherited with it. False Widows no less. They will be ejected at the weekend never to return. I live in an area that has recently been rated special area of conservation so don't want to be responsible for an invasive species. I don't like having venomous spiders around me anyway.

[Hell Razor5543]

I would dose the motors liberally with WD40, as that is exactly what it was created to do (WD stands for Water Dispersant).

[MattBLancs]

Good point about the old grease, I stripped down an angle grinder (bought cheap by my dad, ex-display I think) goodness knows how many years it had sat on display as the grease inside was more like some sort of soft cheese consistency, cut it with a knife a holds its shape! Grim. Ran cooler afterwards unsurprisingly!

WD-40 a good water displacer but pretty terrible long term lubricant. Not sure what's best (other than "full of lubrication Vs full of water" is the way forward!) Will have a think.

[bobins]

If the motor and associated gubbins contains any form of plastic gears then you need the correct type of grease for it.

As a sweeping statement....
"Silicone-based lubricants such as PFAE, most synthetic hydrocarbons (SHC or PAO) and mineral oils work well with plastics. Lubricants based on esters or polyglycols generally do not, although there are exceptions depending on the type of plastic.
If a lubricant’s formulation is incompatible with a plastic part, the part can lose dimensional stability and structural integrity, as well as become discolored."
https://www.machinedesign.com/materials ... d-bearings

[darbuck]

Sorry Lads, I have been up to my neck in work haven't had a chance to get back on really. All interesting points gentlemen, thanks for the input. I think WD40 to clean up the inside followed by silicone grease is probably the best solution given the comments. I was waiting for a bit of input to decide what to do from a regrease point of view. So I think that answers the question. Still no word on the pcb. I don't know if that's a good thing.

[Rp0thejester]

So basically WD-40 to get rid of water and then grease it up afterwards

[darbuck]

Yep with silicone grease to avoid the plastic turning into mushy cauliflower.

[Hell Razor5543]

Yep with silicone grease to avoid the plastic turning into mushy cauliflower.

Just watch out for unexpected enlargements!

[darbuck]

Yeah that's the hope but without knowing the spec for the original grease it's a case of plastic friendly grease i.e. silicone. It shouldn't react I think the plastic is acetyl so should be ok.

[MattBLancs]

Yep with silicone grease to avoid the plastic turning into mushy cauliflower.

Just watch out for unexpected enlargements!

Joke along the lines of "is that an incorrectly lubricated wiper motor in your pocket, or are you just pleased to see me?" almost inevitable at this point!

https://quoteinvestigator.com/2013/08/20/glad-to-see/

[darbuck]

thanks for the comic relief Matt

[myglaren]

I used to work for a company producing electrical test instrumentation and all the PCbs had a 'conformal coating' to protect them. Something I never really delved in to at the time.
I wonder if there is anything that can be used to similarly protect your PCB from corrosion> Possibly Clearcoat?

[MattBLancs]

I couldn't have told you the name of it, but am sure my dad (used to fix TVs) had/has an aerosol spray type product that did that job in his "garage of many useful things"

I'll see if he remembers the name of it. Might be somewhere like CPC / Farnell / Maplins? To get some.