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Wiper Bench test

PostPosted: Sun May 04, 2014 4:59 pm
by William2
Has anyone tried the complete wiper assembly out electrically on the bench using just wires (no switch) and a battery. I am trying to find out on mine (S4 Elan) where the park position is in particular as the motor and gear wheel are all new. Also, from the picture have I assembled the wheelboxes round the correct way and is there supposed to be any packing or metal clip arrangement where the threaded nut assembly slots in to the wiper motor. I have got it working successfully at both speeds but can't fathom out what battery connections to make for the parking switch. I have looked at a lot of the previous threads on this topic!!

Re: Wiper Bench test

PostPosted: Sun May 04, 2014 7:31 pm
by billwill
I have a similar problem, but it is because I have not got the correct connector to plug into the replacement motor.

When you had it apart you should have noticed some electric contacts which are closed over most of the range, but open in the parked position.

The parking circuit is very simple; an unswitched fused supply comes from the battery through the parking contacts to drive the motor. So whenever it is not parked it ignores the dashbpard switch and moves until the parking contacts open.

Now off hand I don't recall whether the dashboard switch operates on the LIVE side or on the Earth side so I can't show the exact diagram. Two speed or variable speed also complicates the issue.

Re: Wiper Bench test

PostPosted: Sun May 04, 2014 8:09 pm
by billwill
How you wire the wiper depends on whether you want to be "as original" or not.

A quick Google shows there are many variations on wiring up wiper motors.

https://www.google.co.uk/search?q=wiper ... 92&bih=701

~~~~~~~~~~~

The modern very slow wipe or rain-detector add-ons work by having an electronic 555 timer operate a relay for about 1 (or 2 seconds) at a long interval determined by a control knob or by rain detector.

The relay drives the motor to start the sweep, then the relay opens before it is completed, but supply is taken over by the park switch, So it completes one sweep (both ways). Then it rests until the relay closes briefly again and the cycle repeats.

Re: Wiper Bench test

PostPosted: Mon May 05, 2014 5:54 am
by john.p.clegg
William
Wiring diagram in this post...

lotus-electrical-f38/wiper-wash-switch-t30523.html?hilit=wiper%20wiring

ignore the W/W and relay,that's just a mod...

John :wink:

Re: Wiper Bench test

PostPosted: Mon May 05, 2014 10:32 am
by TroonSprint
There is an MGB guru called Paul Hunt who has written an extensive web site on these cars. The wipers on a B are identical to the Elan, so it would help you to read that section here http://www.mgb-stuff.org.uk/electricstext2.htm#wipers

Ideally to test the circuit you need the switch connected up because it is in the switch that the park circuit is energised. Looking at the socket on the motor, I have made a diagram of the connections.
WiperMotorConnect.jpg and


As far as the switch is concerned, looking at the back of it,
Upper left is power in and W/G to motor 4.
Upper right is N/G to motor 3.
Lower left is R/G to motor 2.
Lower right is U/G to motor 5.

I wired mine up on the bench like this and it worked perfectly. The blades on the RHD car should park on the drivers side.
Mike

Re: Wiper Bench test

PostPosted: Mon May 05, 2014 5:49 pm
by stugilmour
Here are some materials from the 'net I found helpful. Might be the same stuff others have posted links to. :)

A word of caution on wire colours. Lotus colours for this circuit can be non-standard (i.e. not exactly following British Standard BS-AU7). At least they were in my Plus 2. Long time since I looked at the stock circuit, but I believe they even changed the park circuit wire colour at one of the main loom connectors in my car. :? I provided a 'conversion' of the Lotus colours in my car in the Smartscreen post below that might help you out, although your model may use different colours.

Once you get the wiring at the wiper motor correctly figured out, would recommend adding the correct plug; not sure with your particular model, but mine had separate female spade connectors and it would be easy to mis-wire if disconnected for repair. Can be a bit confusing if a given connector picture is representing the plug or motor side.

I got my plug here, although pretty sure there are other suppliers:

http://www.britishwiring.com/Wiper-Moto ... p/c805.htm

Bill, I successfully added after market Smartscreen intermittent wiping to my Plus 2 and posted some info here. Still happy with the devise, and it is particular to the standard vintage Lucas set-up so the install is not too bad.

elan-mods-f31/smartscreen-intermittent-wipers-review-t25502.html

The Smartscreen functionality is similar to intermittent wiping using a particular Hella timing relay in place of a standard five pin. This is how it works in the Esprit world. I found it worth it to buy the Smartscreen for the Elan to make the wiring easier.



HTH

Stu