Avant rear wiper problem

[Robh]

Hi everyone 

I’m new to the forum and looking for some advice please.

 

I have a faulty rear wiper 

all fuses and cables seem ok and there is a 12v feed at the motor 

if I open the motor and manually move the cog so the arm move about 1cm it springs into life for a few cycles then stops at the park position.

today I have replaced the motor but it’s still the same.

Any advice will be appreciated 

thanks

[Steve Q]

Audi rear wipers are famous for failing and it is due to corrosion through washer fluid leaking into the motor. I would say gears are blocked, because grease has mixed with washer fluid. Remove trim, remove motor, open motor housing, clean, install additional o-ring (so it never mixes again), use new grease (water resistant), close housing, test. If motor circuit is wet, maybe it is broken.

The two wires you measured always have 12V, the other two are trigger from control unit, you cannot measure it with multimeter. 

 

[Ashleyjay]

Hello sorry for jumping on this post. I’m new today and have no idea how to post anything lol. And I’m a woman so go easy on me ha. So my Audi A3 rear wiper hasn’t been working. I couldn’t get the bolt of so was told to grind it off which I did. I have had a new motor fitted onto it today and it still won’t work. What else could it be. Thankyou 

[Magnet]

Hello Ashley,

Worth stripping back the flexible rubber covering over the harness section which links the harness from the bodywork into the tailgate, and inspection the individual wires. 

Often the source of fractures in wires, and always worth looking at before doing anything else.

Kind regards, 

Gareth. 

[Robh]

Hi as Gareth said the problem was a damaged cable 

if you separate all of the cables where the enter the tailgate then give each one a gentle tug you may find the problem.

my damaged cable was just above the roof lining trim panel 

there is a plastic curve that the wiring loom goes through mine was broke there  so a bit of stripping was req also there was two other cables damaged in the same place 

hope this helps

 

 

 

[Magnet]

Thanks Rob,

Often measuring 12v at a point is taken as the wiring is sound.

However, it must be appreciated that meters read voltage at very small current demand, so the 12v in this case (via. theoretically a single strand remaining) may not support the current loading necessary to start and run the motor. 

Kind regards,

Gareth.

[Ashleyjay]

Thankyou all for your kind replies 😊I will try these 

[Steve Q]

20 hours ago, Ashleyjay said:

Thankyou all for your kind replies 😊I will try these 

You're welcome 😊