XJ Wiper motor Relay control system

Revision 3 document 1

Notes:

The relays used can all be the switch type (5 pin) and need to be rated at 20 > amps 

Each relay is clearly marked as to which pin is which.
Pins 85 and 86 are the coils
30/51 is the switch input
Pin 87 is the output when hot (energised)
Pin 87a is the output when cold (at rest) 
switch relay pins switched type relay

All termination should be done with a roll over crimper tool and not the type that crushes the connector. They should all be terminated with slip insulators and 6.35mm female spade connectors.
Crimper crimper

Above and below: These are ok for a quick fix or anyone on a budget. Care has to be taken not to crimp so tight that the insulator cracks as this leads to premature failure. Right: These are the professional type of tools we use and they create a strong rolled over crimp that can also be soldered for added strength

crimper

Insulated spade connector

Wire correctly stripped

 Bullet connector no insulated female spade
Sleeve for above connector

Bulk head Connector: this is the 8 pin plug that fits the receptor under the wiper grille. For reference the pin outs are listed at the end of this article.

Always Disconnect the Battery when working on the electrics or fuel system lines and components. 

Existing wiring modification Method: 

At the plug connector that drops onto the bulkhead connector you will need to do the following: 

  1. Cut the Yellow wire and extended both ends to reach the location chosen to mount the relays. Splice the Yellow wire from the bulkhead plug end to have two ends 

  1. Repeat for the White and Brown wires.

  2. There are instances of the colours being different. 
Signal wiring

New wiring that needs to be added: 

  1. Run two heavy gauge Black wires and four normal gauge black wires from the relay location back to a suitable earth point. The normal gauge wires can be daisy chained so as to provide only one earth connection. 

  1. Connect some heavy gauge Brown wire to the terminal connection on the bulkhead and run this to a length that reaches the relay location splice in a fuse holder on route. 
New feeds negative and positive

Making the earth and 12v+ feed: 

  1. Connect one of the four normal gauge black wires to a relay post 85 and repeat for the other three relays. Alternatively daisy chain pins 85-85-85-85-earth 
  1. Connect the two remaining heavy gauge black wires to pin 87a on two of the relays. Label these as relay 1 and 2  
  1. At the relay location take your new Brown +12v feed and splice in three wires. 
  1. Connect one of these Brown wires to Pin 87 of relay 1 
  1. Connect another one of these brown wires to pin 87 of relay 2 
  1. Connect the third to Pin 30/51 of a relay and label that one relay 3
Hooking up the new feeds

Bulkhead connector wiring relocation: 

  1. Connect one of your two bulkhead connector side yellow wires to pin 86 of relay 3 
  1. Connect the other bulkhead connector side yellow wire to pin 86 of the remaining relay and label it relay 4 
  1. Connect the bulkhead plug end of the cut brown wire to pin 86 of relay 2  
  1. Connect the bulkhead connector end of the white wire to pin 86 of relay 1
Bulkhead connections

Motor connector wiring relocation: 

  1. Connect the Motor end of the Yellow wire to pin 87 of relay 3 
  1. Connect the other end of the brown that goes to the motor connector to Pin 87a of relay 4 
  1. Connect the motor end of the white wire to pin 30/51 of relay 1

Motor hook-ups

Finishing off the installation: 

  1. Using a piece of blue wire connect one end to pin 30/51 of relay 4 and connect the other end to pin 30/51 of relay 2 
  1. Fit a suitable fuse in the fuse holder and reconnect the battery.

Final wiring

Lucas Wiper motor connections Technical details
 
Bulkhead connector viewed as if standing on engine facing windscreen;

  • Ignition to ACC
  • Switch at fast wipe – W/LG post = 12 v+
  • Switch at slow wipe – B/LG post = 12 v+
  • Switch in Intermittent and off  - K/LG post = 12 v+
  • Ignition to Off
  • Continuity between O LG and B LG posts in intermittent/flick and off modes only.
  • Ground pin to ground

The Motor to bulkhead connector is wired as follows:

The plug on the motor is configured as per this diagram below

Pin 1 White
Pin 2 Red
Pin 3 Yellow
Pin 4 Green
Pin 5 Brown

Some harnesses convert to a different colour system:

Pin 1 White (pink/light green)
Pin 2 Red (orange/light green)
Pin 3 Yellow (white/light green)
Pin 4 Green (black)
Pin 5 Brown (black/light green)

On the opposite side of the Park switch the exiting wires are:

Pin 5 (brown or Black/light green) goes to Red (slow)
Pin 3 (Yellow or White/light green) goes to Yellow (fast)
Pin 1 (White or Pink/light green) goes to Blue (both speeds)