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Smartscreen unit - click for larger size

Smartscreen Intermittent Wiper/Washer Control

August 2009 (Addition)

Intermittent wipers are something which we take for granted in modern cars but it is not something which is standard on the old MGs (and thus not on NGs either). Fortunately Smartscreen do a range of electronic wiper controls which do not require an extra switch and can be fitted in a concealed position maintaining the vehicle's original look.

The principle of operation is that a repeat is 'programmed' using the standard wiper switch. The Smartscreen unit remembers the interval (anything between 3 and 30 seconds) between switching and repeats it. An additional feature of the unit I fitted (the SS05/P) is that the wipers are triggered for a few wipes whenever the electric washers are used.

Smartscreen fitted - click for larger size I should point out here that the 'normal' unit with washers recommended for the MGB is the SS05/N as its washer switch is between the washer pump (which is connected to +12v) and earth. The Smartscreen is therefore triggered from the negative side of the pump - thus the 'N'. However, on the NG we normally connect the washer pump between the washer switch (which is connected to +12v) and earth. The Smartscreen is therefore triggered from the positive side of the pump - thus the 'P'. (My thanks to Smartscreen for explaining this to me). I understand that most MG suppliers stock the 'N' version so, if you want the 'P' version, I think it is best to order direct from Smartscreen as I did. There are also other units available though which do not have the wash/wipe facility.

Electrical Connections

Smartscreen wiper wiring - click for larger size The fitting is quite straighforward, the majority of the 6 connections being in the vicinity of the wiper switch. The bladed terminals are labelled (from L to R) Sw, -ve, +ve, W, Wsh, P and are connected as follows (see diagram):
  1. connect Sw to the first speed wiper supply terminal on the wiper switch (terminal 6 on my Lucas toggle switch), remove the existing wire (to the motor) and connect to W (red/light green)
  2. connect -ve to a convenient earth (black)
  3. connect +ve to live feed - easiest to tap into the supply on the wiper switch (terminal 4, green)
  4. connect Wsh to washer switch terminal which supplies the pump (light green/black)
  5. connect P to the park terminal on the switch (terminal 2, brown/green)
After testing, I simply cable tied the unit up behind the dashboard out of sight. Now for some light rain to test it in earnest - I shouldn't have to wait too long!