How to add rear washer to rear wiper

Old 01-29-2011, 01:17 AM
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Location: san jose california
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Default How to add rear washer to rear wiper

This is a how-to for adding a rear washer to the rear wiper for 964 cars. In the end it will look like this:

It functions by using the intensive washer setup but doing some rerouting of hoses and some rewiring. My car is a 1992 and the intensive washer was not an option. I added it for this purpose

The apparatus uses a rear washer nozzle setup from a Volvo and fits in the rear wiper spindle after some machining is performed. The machining is not a straight through same size hole, but has a shoulder machined within to position the two piece washer nozzle assembly, including an o-ring.

Route the supply hose from bottle into fender and along the oil lines to the back and up into engine compartment. Then snake it though hole with electrical harness to rear shelf area, connect to washer nozzle and secure in place with rubber hold down.

If you don’t have the intensive washer setup, you will need to get the switch, relay, pump, and washer fluid bottle.

Relay goes in position 53, PH means bought from Parts Heaven.

Turn relay carrier over, bang out cross bar with rubber mallet and that releases the connectors

Pull out O connector.

Now you will have to disassemble the O connector. It is made up of 5 sections. 1 red, 3 black and 1 green. The red has the locking tab that is secured by the cross bar. carefully pry the sections apart. The pic below is of a typical connector separated.

You will need to add some connectors. You can order the separate wire terminal connectors (999.652.451.22) or buy a cutoff harness connector (Parts Heaven) and take it apart for the leads you will need. You will need some thin wire tools to remove the wire connectors from the holders. I made mine by grinding 1/16 drill bits to have a flat side.

The O connector block has 4 rows of 5 connectors each. Shine a flashlight into the relay carrier and you will see each terminal position is marked. Row 1 has connector 11,12,13,14, and15, etc.

The wiring connections are as follows.
relay pin #___socket pin#___harness connector___connection
___30__________3_____________O 31_________connect to dash switch and splice into L 31
___87__________5_____________O 15_________connect to + of washer pump
___31__________2_____________O 13_________make a jumper to J 22
___15__________1_____________O 35_________connect to dash switch
____S__________6_____________O 32_________is + 12 volts when pump is activated so splice to green wire on rear wiper switch so wiper is activated when washer operates
____T__________7_____________O 24_________not used
_______________4___________not used
_______________8___________not used
_______________9___________not used

L 31 is the wire into the 3rd row 1st position of the L relay harness connector, it should be there already. it provides power to the heated front washers for heating
The jumper to J22 may be there, if not you will need to pull J block connector out and separate it to add the jumper connection.

Now if you have the intensive washer setup and want to convert to rear washer you will need to cut and plug the hose coming from the intensive pump and add new hose to rear.
You will also need to do some rewiring. You will need to cut the green/red wire coming out of O 24 and tape over as it is not used. Then cut wire jumper from O 32 to M 43 and connect O 32 as above.

Last edited by stevepaa; 02-03-2011 at 03:10 PM.
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