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Wiper Woes

PostPosted: Mon Sep 12, 2016 9:50 pm
by gavk
Evening all.

Apologies if this topics been done to death but I've not found any specific answers in the forum search.

Since owning my car the wiper system has been 'Characterful' to say the least. I'm interested to know if this character is normal behaviour in a +2 or if some improvements can be made?

Current Status:

1. Wipers don't start when switched to 'Slow' (1Click).

2. If I switch to 'Fast' (2 Clicks) they work and continue to work when switched back to 'Slow'.

3. Wipers only work on a wet screen. It seems friction is too great on a dry screen (thoughts on this later).

4. Wipers only park if I time switching off at the bottom of the wipe. If I switch off any other time then I see the voltmeter drop as the wipers struggle to park themselves.

All of the above leads to a merry dance of ensuring that the screen is kept wet enough with screen wash for me to get wipers to bottom of stroke before I switch off!

My thoughts:
It's caused by one or all of the below.
1. Motor and or wiper racks need clean & fresh lube to reduce friction

2. Wipers pressing too hard on screen, reduce spring force to compensate

3. Poor electric connection(s) in system

4. Any other thoughts?

Cheers,

Gavin

Re: Wiper Woes

PostPosted: Mon Sep 12, 2016 10:04 pm
by Elanintheforest
Number 1 and 3 seem to be the most likely reasons Gavin. My S3 had similar problems, and I found grease in the rack and wheel boxes that had set hard, and poor electrical connections. The motor commutator needed a good clean as well.

After 45 years it's hardly surprising, and I'm sure that Chapman would be furious that some components were so over-engineered as to be still functioning at all 30 plus years after their planned life!

Mark

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 2:10 am
by Wickey
You may obviously have a combination of issues here. However a couple of other ideas...

Firstly the two speed window switch sounds like possibly just dirty contacts. There is an old and recent thread just being discussed on changing or cleaning that switch.

lotuselan-plus2-f51/replacing-window-switch-t38000.html

lotus-electrical-f38/wiper-switch-from-ray-dent-t32124.html#p215606

You can try repeatedly switching on and off without going to fast speed and just see if you can get any movement as when the switch contacts get dirty they can cause enough resistance to prevent electrical contact. It is only an opinion but I think what may happen is as current flows through the switch on high speed the inside contacts get quite warm and the heat may break down some of the contact surface resistance and then when switched to slow allows the circuit to be made.

Also the two wiper boxes are a usual suspect as the shafts do wear inside and the spindles over the years and may need replacing. You can try getting some release oil or WD40 down the shafts from outside the car it may help lubricate. They were common standard fitment on a few British cars MGB/Triumph/Lotus etc. Check and see if there is any free play and wear between the shaft and spindle by holding the splined shaft and rattling side to side. Its a real hard one here though to determine because as the shafts wear water tends to seep in between the spindle and shaft which then causes oxydisation. This can then virtually build up inside and causes extremely high rotational resistance. Removing the wiper motor and drive cable will allow you to fully check these though and see if they are freely moving and not stiff to turn.

Both of these.... switch and wiper boxes..... can be fidly to replace but again a lot of detail on that in the other thread so best to try all the simpler other options offered.

As for wiper pressure take the wipers off and see if the splined shafts are turning freely without the wiper blade pressure...Then just put one back on at a time which should reduce pressure and see how each wiper box performs with just one wiper working... ideal time to spray in some lubricant too down the shaft. It also helps if you have a water sprayer on hand and keep the windscreen wet while doing any testing. Also old rubber blades can go hard and the rubber blade has to actually rock over/pivot along its length to perform properly, but I doubt just this would give you your issue..

You can easily remove the whole wiper motor and drive cable. There is a guide tube the motors flexible drive slides into so it is easily slid back. Clean and regrease the drive cable. The position of the wiper wheelbox spindles does not matter as that is compensated by the wiper arm fitment on the splined shaft but it is a good idea to mark the parked position and try and get the wiper box spindles to finish 180 degrees rotated when the wiper motor drive cable is reinserted. This can be 'fun' and a bit hit and miss but the interior cog on the wiper box that is driven by the wiper motor cable only uses a third of the cog teeth and as these wear it is useful to try to align the refit onto some fresh unused cog teeth.

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 8:25 am
by gavk
Thanks for all the information guys, some great stuff there.

It's good to hear that it's not just the way it is and that there is room for improvement!

I have already replaced the switch so first suspect will be re-lubricating as much as possible.

I hear Wickey's tip about lubricating the wiper spindle from the outside but what's the alternative to get full access to the wiper racks? Is it a dash out job?

Thanks again,
Gavin

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 9:02 am
by Wickey
gavk wrote:I hear Wickey's tip about lubricating the wiper spindle from the outside but what's the alternative to get full access to the wiper racks? Is it a dash out job?

Thanks again,
Gavin


Obviously what you call the wiper racks I refer to as the wiper wheel boxes. Most cars I have had it has been a dash out job but good question to ask if anyone has managed to replace them from the footwells. Take the easy option first and remove the wiper motor and cable drive. That should allow free turning of the spindles and if they are just a bit stiff and corroded inside you can often get enough release oil down between the shaft and spindle to work them free. Gravity and capillary action should help draw in the release oil. The problem is the shaft is plated and the spindles and oxydisation will usually have eaten through the plating so you need to then keep them well oiled then when you can. If you can make some type of funnel by wrapping tape around the outer thread of the shaft and allow the release oil time to be drawn down it helps. The guy who fixed mine had a small tube he had threaded internally and used to remove the chrome hex nut and screw the tubes in place then squirt release oil in the tube and leave for a bit until it seeped down the shaft. Problem is with just trying to spray it down even with the plastic tube some cans supply for the nozzle most ends up over the bodywork..

I don't think there is any advantage in trying to think you can lubricate anything from inside under the dash.

Pulling the motor and drive cable out should dislodge any old grease in the guide tube and if you liberally regrease the drive cable when refitted most will end up around the wheel box cogs anyway. You will not be able to access the spindle and shaft from underneath the dash for any lubrication purposes as the cog wheel will block your access.


The fact you have already changed the switch eliminates that hopefully as the problem.

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 9:06 am
by john.p.clegg
Change the wiper park switc and check the wiper motor body earth.
John

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 11:21 am
by Grizzly
As above..... When i assembled mine i found it was running slow so i hooked it up to a Power Probe and it was still slow so i had my Wiper motor rebuilt, it was better but still not Modern car standard. But i think on an elan everything should start with a good ground.

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 1:25 pm
by stugilmour
Gavin, this thread has good information, including the repair manual

lotus-electrical-f38/windshield-wiper-motor-t22685.html

HTH

Stu

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 1:45 pm
by Craven
Hi,
May help, took me a while to find this little gem.
Ron.
wiper-switch.png
wiper-switch.png (7.26 KiB) Viewed 1802 times

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 3:15 pm
by collins_dan
When I replaced my switch, slow would not work either. It ended up that the new switch was a mirror (left/right) image of the switch I had replaced. You might try checking the posts to see if you are connecting to the correct post for the slow circuit. Good Luck. Dan

Re: Wiper Woes

PostPosted: Tue Sep 13, 2016 5:15 pm
by The Veg
I'm glad you guys brought all this up when I have my dash out; I wouldn't have thought of it otherwise!

One more sub-project on the list! :mrgreen:

Re: Wiper Woes

PostPosted: Wed Sep 14, 2016 9:49 am
by vincereynard
Wickey wrote:it is a good idea to mark the parked position and try and get the wiper box spindles to finish 180 degrees rotated when the wiper motor drive cable is reinserted. This can be 'fun' and a bit hit and miss but the interior cog on the wiper box that is driven by the wiper motor cable only uses a third of the cog teeth and as these wear it is useful to try to align the refit onto some fresh unused cog teeth.


Wickey's suggestion of assuring the box spindles are turned 180 degrees is a good tip, I've used it myself a number of times. See if you can also turn the rack over, then you will have new rack meshing with new gear.
(Assuming it has not already been done at some time!)
You may have to swap the plastic block on the wiper "crank" to park on the correct side. I've done this on a Tr Dolomite wiper motor, which is probably very similar.

Re: Wiper Woes

PostPosted: Wed Sep 14, 2016 10:16 am
by gavk
Brilliant information, thanks all.

I attempted to lubricate the wiper racks/wheel boxes by forming a well around each one last night.

Today I can see a marginal improvement, I think I'll do it again and when I have a bit more time I'll clean and regrease the wiper motor gearbox.

If that fails to make the difference then I'll move on to the many good suggestions in this post.

For anyone else reading this, I found a YouTube video about the workings and design of these motors which is quite interesting and has some useful discussion of the parking switch
https://youtu.be/a7qJy8mYi6s

Re: Wiper Woes

PostPosted: Wed Sep 14, 2016 11:37 am
by gus
It's the wiring

first 12 years I owned my car the wipers would not work on a dry windshield or when the car was not charging

rewired and most importantly re grounded the wipers

just like a real car

it is probable every connection back to the fuse box is crap

check them all

Re: Wiper Woes

PostPosted: Wed Sep 14, 2016 4:02 pm
by Wickey
The Veg wrote:I'm glad you guys brought all this up when I have my dash out; I wouldn't have thought of it otherwise!

One more sub-project on the list! :mrgreen:


Glad you are sorted Gus :D

One other great idea I saw on the the Plus 2 with the 'questionable' purple roof that the guy had done when he replaced the dash was making a loop from bicycle cable and feeding it through the bulkhead each side then around the bonnet release triggers. So if ever the bonnet pull cable broke he just had to pull the cable from under the footwells each side and it released the bonnet latches. IIRC he said he had once a rotted/broken/seized cable for the boot release latch on one of his other Lotti and they had to cut through the body behind the number plate as it was damaged inside the boot. Not sure how anyone gets into the engine bay or boot if the cable pull breaks, but I am sure someone must have done it.

I think if you look closely at the picture you can just make out the cable looped around the left latch........hope he told the new owner but a simple job to do when the dash is out :idea: