Wipers

[Mark.stephenson485]

I have fitted a new wiper motor wheelboxes and wire.
The wipers work sometimes but I occasionally have to pull the blades to get them working.
Any suggestions what maybe wrong?

[svenedin]

Did you overhaul the motor? I suspect it is full of hardened old grease. Did you remove and clean out the Bundy tubes and thoroughly grease the new wiper rack?

Stephen

[geoberni]

Sounds to me like the motor is struggling.
Either as Stephen suggests, the Motor & Gearbox needs a good overhaul, or you've not assembled it all correctly and something is a bit stiff/binding.

[simmitc]

The OP stated "I have fitted a new wiper motor wheelboxes and wire.". If it really is a new motor then it shouldn't be full of hardened grease. It sounds like a major refurbishment of the system, which means disassembly and reassembly of all components, so there is a risk of damage to the tube.

I am, wary of new wheel boxes as those currently available do not usually have the correct number of teeth and will affect the sweep unless the gearwheel in the motor is changed to match.

It could be a loose electrical connection and the act of moving the arms produces a nudge further down.

I suggest:
Remove the arms.
Remove the motor and rack.
Check that the wheel boxes spin freely.
Insert the rack and pull backwards and forwards by hand to check that there is no binding.
If available, refit the old motor and test. If all OK, then fit the new motor. Either the problem will have been resolved or if the fualt is still present, then it confirms that it lies wit the new motor..

[oliver90owner]

My first question would be; Is the motor drawing current when the wipers refuse to start? If not, it is electrical contact, not overloading due to friction.

[geoberni]

The OP stated "I have fitted a new wiper new wiper motor wheelboxes and wire. and wire.". If it really is a new motor then it shouldn't be full of hardened grease. It sounds like a major refurbishment of the system, which means disassembly and reassembly of all components, so there is a risk of damage to the tube.

I know what you mean, but from past experience of long distance diagnosis, I wasn't necessarily taking as verbatim the 'new wiper motor, new wheelboxes and new wire'. People often use 'new' when they actually just mean replacement.
Motor might be a salvage item, or they might mean just the 'wheelboxes' rather than 'wiper motor and wheelboxes'.

I'm erring towards something not quite being fitted correctly, over-tighted, kinked drive cable, or something, hence why it starts after being given a nudge.

First thing I'd be trying is does the motor operate off load, without the drive cable attached?

[svenedin]

It's a big job to overhaul the whole wiper system and I certainly did not enjoy it!

We need more detail of exactly what was done. It is possible to pinch the Bundy tubes where they enter the wiper wheel boxes and that would cause the rack to be stiff. I found the tubes full of the muck of ages and I cleaned them all out. Reinstaling the greased rack cable is a very messy and slippery job. I did a trial run of operating the cable by hand to make sure it ran smoothly. The most likely bit of tube to end up at a silly angle is the first section from motor to first wheel box.

Simon is correct that none of the currently available new wheel boxes have the correct number of teeth and this affects the swept area of the screen.

Stephen

[TOMO28B]

Just a thought,I had a problem with the wipers when they packed in altogether. Once I got outside between heavy rain bursts,I then done a bit of detective work and traced the earth attached to the motor itself. It looked sound,but was actually very slightly loose and the metal work was badly corroded.once filed shiny and new washer each side of the bolt, it was back to business. Quite obvious I suppose but hopes it helps.