Screenwashers Front And Rear Low Pressure

[abzeng]

I have a Feb 2003 D4D Avensis. For some time the screen wash has had very low pressure at the jets. I have taken the bottle out and cleaned the whole system- nil fix. Bought two used pumps and fitted - hardly any improvement. Nozzles are all clean. Can anyone tell me where the relays are for front and rear? I have been told the brushes wear in the pump motors and speed falls off. anybody know where you can download toyota wiring diagrams at reasonable price? New Pump from toyota is £53!!!!!!!!!!

[abzeng]

:)

I have a Feb 2003 D4D Avensis. For some time the screen wash has had very low pressure at the jets. I have taken the bottle out and cleaned the whole system- nil fix. Bought two used pumps and fitted - hardly any improvement. Nozzles are all clean. Can anyone tell me where the relays are for front and rear? I have been told the brushes wear in the pump motors and speed falls off. anybody know where you can download toyota wiring diagrams at reasonable price? New Pump from toyota is £53!!!!!!!!!!

Finally solved this one myself! did get some wiring diagrams from toyotatech document website and realised front and back pumps work on earths to car chasis. These are two separate earth points BUT there is one common earth where a small black lead comes from the Battery to the car body just left of the top of the radiator just under tyhe bonnet. The crimp terminal looked a little bit corroded and there was no bare metal contact between it and the car body. The earth connection was relying on contact of attaching bolt to the nutplate threads - all seemed to have lots of good toyota factory paint around them! Cleaned the crimp terminal and a small area of paint removed below it - what a difference less resistance makes! :) :)

[Q.S.]

:)

I have a Feb 2003 D4D Avensis. For some time the screen wash has had very low pressure at the jets. I have taken the bottle out and cleaned the whole system- nil fix. Bought two used pumps and fitted - hardly any improvement. Nozzles are all clean. Can anyone tell me where the relays are for front and rear? I have been told the brushes wear in the pump motors and speed falls off. anybody know where you can download toyota wiring diagrams at reasonable price? New Pump from toyota is £53!!!!!!!!!!

Finally solved this one myself! did get some wiring diagrams from toyotatech document website and realised front and back pumps work on earths to car chasis. These are two separate earth points BUT there is one common earth where a small black lead comes from the Battery to the car body just left of the top of the radiator just under tyhe bonnet. The crimp terminal looked a little bit corroded and there was no bare metal contact between it and the car body. The earth connection was relying on contact of attaching bolt to the nutplate threads - all seemed to have lots of good toyota factory paint around them! Cleaned the crimp terminal and a small area of paint removed below it - what a difference less resistance makes! :) :)

Good to hear you got a fix done. A voltage drop test at the pump terminals should have shown up the fault (voltmeter between the neg pump terminal and Battery negative with pump operating should show around 0.5V or less). I suspect that there would be a few other systems suffering from the high resistance too.

[abzeng]

:)

I have a Feb 2003 D4D Avensis. For some time the screen wash has had very low pressure at the jets. I have taken the bottle out and cleaned the whole system- nil fix. Bought two used pumps and fitted - hardly any improvement. Nozzles are all clean. Can anyone tell me where the relays are for front and rear? I have been told the brushes wear in the pump motors and speed falls off. anybody know where you can download toyota wiring diagrams at reasonable price? New Pump from toyota is £53!!!!!!!!!!

Finally solved this one myself! did get some wiring diagrams from toyotatech document website and realised front and back pumps work on earths to car chasis. These are two separate earth points BUT there is one common earth where a small black lead comes from the Battery to the car body just left of the top of the radiator just under tyhe bonnet. The crimp terminal looked a little bit corroded and there was no bare metal contact between it and the car body. The earth connection was relying on contact of attaching bolt to the nutplate threads - all seemed to have lots of good toyota factory paint around them! Cleaned the crimp terminal and a small area of paint removed below it - what a difference less resistance makes! :) :)

Good to hear you got a fix done. A voltage drop test at the pump terminals should have shown up the fault (voltmeter between the neg pump terminal and Battery negative with pump operating should show around 0.5V or less). I suspect that there would be a few other systems suffering from the high resistance too.

[abzeng]

:)

I have a Feb 2003 D4D Avensis. For some time the screen wash has had very low pressure at the jets. I have taken the bottle out and cleaned the whole system- nil fix. Bought two used pumps and fitted - hardly any improvement. Nozzles are all clean. Can anyone tell me where the relays are for front and rear? I have been told the brushes wear in the pump motors and speed falls off. anybody know where you can download toyota wiring diagrams at reasonable price? New Pump from toyota is £53!!!!!!!!!!

Finally solved this one myself! did get some wiring diagrams from toyotatech document website and realised front and back pumps work on earths to car chasis. These are two separate earth points BUT there is one common earth where a small black lead comes from the Battery to the car body just left of the top of the radiator just under tyhe bonnet. The crimp terminal looked a little bit corroded and there was no bare metal contact between it and the car body. The earth connection was relying on contact of attaching bolt to the nutplate threads - all seemed to have lots of good toyota factory paint around them! Cleaned the crimp terminal and a small area of paint removed below it - what a difference less resistance makes! :) :)

Good to hear you got a fix done. A voltage drop test at the pump terminals should have shown up the fault (voltmeter between the neg pump terminal and Battery negative with pump operating should show around 0.5V or less). I suspect that there would be a few other systems suffering from the high resistance too.

Yes at least one I noticed last winter- the rear screen heater was a bit weak and intermittent sometimes. Now that the bad earth is fixed I have noticed the air con seems to work better as well!