The Triumph Dolomite Club - Discussion Forum

davidmorr wrote: ↑Wed Feb 16, 2022 10:43 pm

cliftyhanger wrote: ↑Tue Feb 15, 2022 8:47 am I have found the grease inside the motors (or the drive mechanism) can be hard/crusty. Opening it up, cleaning out and a regrease really helps. Likewise the engire moving mecahnism responds well to a clean/regrease.

I suspect this is the issue. I will pull it apart at the weekend. Is any particular type of grease needed for the wiper motor?

I used wheel bearing grease as that is what sits on the shelf. It is pretty general purpose.

cleverusername wrote: ↑Mon Feb 14, 2022 7:25 pm Before taking the dash out I would unplug the motor and check it. Use a multimeter to check it is getting 12V and wire it up to a 12V supply to see if it runs at normal speed.

Having now had a good look at the motor and under the dash, how do you get to the electrical connections? On my car, the cables go from the engine bay under the wiper motor where they are not visible or reachable. The other end of the cables goes into the wiring loom so not detachable there to check.

Edit: Ah, I see you need to remove the motor.

cliftyhanger wrote: ↑Tue Feb 15, 2022 8:47 am I have found the grease inside the motors (or the drive mechanism) can be hard/crusty. Opening it up, cleaning out and a regrease really helps. Likewise the engire moving mecahnism responds well to a clean/regrease.

I suspect this may be the case. We have had wet weather here lately so I have had to use the wipers. They have improved with use, probably close to original function. But it is probably time to take out the motor and replace the grease.

A couple more things:

When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

The ends of the blades do not touch the screen, leaving a fair bit of the screen unwiped, especially on the driver's side. The arms are pretty old, and I suspect the springs holding them to the screen have lost their tension. Are replacement springs available, or should I just get new arms? Or is there some other way to get the blades to maintain full contact with the screen?

davidmorr wrote: ↑Fri Feb 25, 2022 10:56 pm A couple more things:

When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

The ends of the blades do not touch the screen, leaving a fair bit of the screen unwiped, especially on the driver's side. The arms are pretty old, and I suspect the springs holding them to the screen have lost their tension. Are replacement springs available, or should I just get new arms? Or is there some other way to get the blades to maintain full contact with the screen?

The hesitation is indicative of a potential fault in the park circuit, it's just not fully developed yet!

The blades not conforming to the screen (especially at the end of the arc on the O/S) is pretty much endemic and is more to do with the quality and performance/design of the blade than the arm spring tension. Of course if the spring is tired and floppy, that doesn't help! But the point of steepest curvature of the screen doesn't conform exactly with the hinge in a standard blade. So it can't usually make the required angle change. Back in the 70s there were blades that used dual curved piano wire frames and those worked well on Dolomites. Unfortunately I haven't seen any for more years than I care to remember. IIRC they were OE on certain British Fords.

Steve

Carledo wrote: ↑Sat Feb 26, 2022 1:30 am

davidmorr wrote: ↑Fri Feb 25, 2022 10:56 pm A couple more things:

When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

The hesitation is indicative of a potential fault in the park circuit, it's just not fully developed yet!

Hmm, is the park circuit an electrical thing or is there a mechanical component in the motor that drives this?

davidmorr wrote: ↑Sat Feb 26, 2022 1:39 am

Carledo wrote: ↑Sat Feb 26, 2022 1:30 am

davidmorr wrote: ↑Fri Feb 25, 2022 10:56 pm A couple more things:

When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

The hesitation is indicative of a potential fault in the park circuit, it's just not fully developed yet!

Hmm, is the park circuit an electrical thing or is there a mechanical component in the motor that drives this?

The park switch is an electrical switch that works off a contact on the rotating driven gear inside the motor. If you strip the motor to replace the grease (which will be near enough solid by now) you will find it. It's pretty self explanatory when you're looking at it. May well be the bad grease that is hindering it's function.

Steve

davidmorr wrote: ↑Fri Feb 25, 2022 10:56 pm When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

Oh further examination, I realise that if I turn the wipers on properly, there is no hesitation. It is only when I use the flick switch to do a single wipe that there is hesitation. With even more investigation, it appears that the stalk is sticking when I release it after the flick. Presumably this is resulting in the park circuit not being activated and hence the hesitation.

I have yet to investigate the switch mechanism fully, but the stalk goes into a plastic rectangular piece which pivots between two other rectangular pieces. It looks like it might be friction between those parts and perhaps it needs lubricating in some way. What sort of lubricant would be suitable for this?

cliftyhanger wrote: ↑Tue Feb 15, 2022 8:47 am I have found the grease inside the motors (or the drive mechanism) can be hard/crusty. Opening it up, cleaning out and a regrease really helps. Likewise the engire moving mecahnism responds well to a clean/regrease.

This has been my experience too.

davidmorr wrote: ↑Tue Mar 01, 2022 2:44 am

davidmorr wrote: ↑Fri Feb 25, 2022 10:56 pm When I first turn the wipers on, the arms start to move, then hesitate for a fraction of a second about 30 degrees angle, then continue to move over the screen. On subsequent sweeps, there is no hesitation.

Oh further examination, I realise that if I turn the wipers on properly, there is no hesitation. It is only when I use the flick switch to do a single wipe that there is hesitation. With even more investigation, it appears that the stalk is sticking when I release it after the flick. Presumably this is resulting in the park circuit not being activated and hence the hesitation.

I have yet to investigate the switch mechanism fully, but the stalk goes into a plastic rectangular piece which pivots between two other rectangular pieces. It looks like it might be friction between those parts and perhaps it needs lubricating in some way. What sort of lubricant would be suitable for this?

The one wipe facility runs entirely off the park switch on the motor. You trigger it off the main power, but as soon as you release the switch, park power finishes the stroke.

Steve