Windscreen wiper diagnostics advice?

[Juddder]

After some advice please

What's the easiest way to try and work out why my windscreen wipers have decided to give up the ghost and not move anymore?

I checked the 25A fuse at position 16 which is labelled Wipers, mirrors in the 4.2 handbook and that continuity tests fine

With the engine engaged, but not started, I can hear the relays click in the Wiper Control Box as I go through the wiper modes on the steering wheel button (once, slow, fast, off)

I'm guessing next step is to disconnect the power plug to the wiper motor and check that I am getting +12V on S(low) and F(ast) as I go through the modes and that the + and GND are registering +12V

I believe the wiper unit is a Lucas one similar to that on many Triumphs so this page seems to have the correct pin diagram for the connector

But.. after that where do I go?

Unbolt wipers and disconnect motor? Add +12V to motor directly and see if they go? Try moving wipers by hand (have tried gently and they move a bit up and down but not a lot and don't feel like they are trying to swipe)?

All advice much appreciated

Edited by Juddder on Wednesday 13th March 17:51

[Byker28i]

If you take the wipers off the windscreen, is there any attempt at movement at all?

[Juddder]

Byker28i said:

If you take the wipers off the windscreen, is there any attempt at movement at all?

Thanks

Yes, did try that by putting them both vertical thinking that maybe they were just being crap and had got stuck / frictioned to the windscreen, but they didn't even move when I did that.

I sprayed the top nuts and the mount screw parts with some GT-85 PTFE lubricant last night to see if that helps - otherwise it's driving to it's service at the garage in the rain tomorrow with no wipers (*luckily three roads away)

Edited by Juddder on Thursday 14th March 10:16

[ukkid35]

Time to get some Rain-X or some Gtechniq G5

[Juddder]

ukkid35 said:

Time to get some Rain-X or some Gtechniq G5

Thanks Paul - started the car, no wipers but very little rain so made it to the garage all fine

Parked the car up to talk to the reception and then on return car refused to start and we had to push it as the battery was low - you have to love TVRs

So when I get the car back (it's on trickle charge at the garage) then it sounds like it's wiper motor out and testing as per this thread which has this nice video of the motor running for diagnostics

Also the whole wiper motor removal is very nicely documented with pictures (for a 4.5) from our man in Luxembourg

Edited by Juddder on Friday 15th March 10:38

[Adrian@]

Best advice is that you return to the car and disconnect the wiper motor (do not touch the magnet housing it might be very hot). A@
Re the links you are pointing people at...the upgrade 'motor' (armature, brush set and yoke NOT any part of the gearbox is looked at) was modified to be shorter (it does not change the issue that they changed the brush points inside which simply moves one speed nearer to two speed and the torque start is higher OR the fact that it is still able to be built to run in reverse and strip gears).
It would help that the cerbie stuff has the correct listing for the 19mm ferrule nut size.
A@

Edited by Adrian@ on Friday 15th March 11:07

[Juddder]

Adrian@ said:

Best advice is that you return to the car and disconnect the wiper motor (do not touch the magnet housing it might be very hot). A@
Re the links you are pointing people at...the upgrade 'motor' (armature, brush set and yoke NOT any part of the gearbox is looked at) was modified to be shorter (it does not change the issue that they changed the brush points inside which simply moves one speed nearer to two speed and the torque start is higher OR the fact that it is still able to be built to run in reverse and strip gears). A@

Edited by Adrian@ on Friday 15th March 11:04

Hi Adrian

Thanks for the continued advice and don't worry I wasn't recommending any other motor - just citing those posts for how to remove it and as threads I have been reading

You will maybe have noticed I even amended the citation on my Cerbera Parts website to include your advice, rather than the previous quotes for mini boxes which as you point out from your experience don't work as expected

https://www.alexjudd.com/cerbera/parts/

[Adrian@]

I have posted to you directly...it IS possible for the motor to be LIVE now even with the ignition off.
The fact that you ran the car and it failed to start IMHO means you had a dramatic drain, simply by trying your wipers, it MAYBE that your motor is stuck live and the windings will absorb 12V into the magnet housings before igniting (the reason for not touching the yoke). A@

[Juddder]

Adrian@ said:

I have posted to you directly...it IS possible for the motor to be LIVE now even with the ignition off.
The fact that you ran the car and it failed to start IMHO means you had a dramatic drain, simply by trying your wipers, it MAYBE that your motor is stuck live and the windings will absorb 12V into the magnet housings before igniting (the reason for not touching the yoke). A@

Hi Adrian - I'll reply over email too but I just went back to the garage and checked and there is no heat on the motor casing for the wiper motor at all, and the battery is happily trickle charging at 13.3V so it feels like to me that is hopefully not the case

Probably more like what the car normally does which is start first time with a low battery and then not have enough run to charge the battery fully up again - the garage is 3 roads away / 5 minutes max

Worst comes to worst I can cut the negative wire to the motor and the fix that later as and when

[Byker28i]

I feel your pain with no wipers. My ribbon cable broke the day before going to Classic Spa one year and I drove there and back in rain relying on rain X and speed to clear the windscreen. No horn or main beam either.

When I replaced mine, it was rebuilt by someone offering the service to butch it up, sorry can't remember who as done vis Neil Garners at the time. We tried the TVR Parts replacement uprated but it wouldn't fit my early car

[Juddder]

Byker28i said:

I feel your pain with no wipers. My ribbon cable broke the day before going to Classic Spa one year and I drove there and back in rain relying on rain X and speed to clear the windscreen. No horn or main beam either.

Thanks - yes seems to be a problem we are all going to have at some point so I think as yourself and Paul say Rain X is the short term way to go while I diagnose the problem - that way I can still use the car and hopefully we are through the worst of the UK weather for the year!

Car back from the garage all fine yesterday (they said thanks for bringing something "interesting" in to them on a Friday ) and no heat on the wiper motor so think it's all safe

[Byker28i]

Powers charge £230 plus vat to rebuild your motor
https://powersperformance.co.uk/store/slug/wiper-m...

Adrian used to fix/upgrade/repair them, but that was 10 years ago now
https://www.pistonheads.com/gassing/topic.asp?h=0&...

Could still be doing it?
https://www.pistonheads.com/gassing/topic.asp?h=0&...