Rear wiper

[Modmytop]

Tailgate wiper has stopped in furthest position from parked. Stripped trim out to have a look. The pipe to the washer jet was not fitted correctly, so there has been a small leak, but don't think this had anything to do with wiper problem. Cable to wiper has 3 wires. Haynes manual shows pin 1 through motor to pin 3 to earth (or other way round). Meter showed 12V pin 1 to pin 3 for few seconds after switch operated. I thought it might be high impedance through relay, so stuck 2 ohm resistor between these pins. Still driving good volts, so relay OK.

From earlier related post on this forum, Rustscrat mentioned wiper returns a signal to the BSI. Rustscrat can you explain please how the wiper is controlled? i.e. how does it sense full wipe and then perform reverse wipe? At least the wiper motor is easy to get at.

[Rustscrat]

Here's the diagram. Where the red "x" is, seems to me a mistake in the drawings so ignore this line.
If it's not working at all now, check fuse 11 in the Bsi.
I'm not familiar with the rear wiper - is it on all the time or is it intermittent when switched on and working correctly. cratch:

   

[Modmytop]

Here's the diagram. Where the red "x" is, seems to me a mistake in the drawings so ignore this line.
If it's not working at all now, check fuse 11 in the Bsi.
I'm not familiar with the rear wiper - is it on all the time or is it intermittent when switched on and working correctly. cratch:

Its stopped in the furthest point from parked. No movement at all
now. Checked fuse 11, it was/is OK.

Voltage on pin 1 to pin 3 of connector for a second or 3 after operating switch.

Still not clear to me how motor and BSI (via relay) work to swing motor both forward and back ??

[Modmytop]

So how do the front wipers work? That is, what makes the motor turn in reverse, if indeed it does? What sensors are involved etc?

[Rustscrat]

Sorry for not replying sooner but been away. Will reply tomorrow.:thumbsup:

[Rustscrat]

Sorry for not replying sooner but been away. Will reply tomorrow.:thumbsup:

Usually it's the mechanism inside the motor gearbox that causes the forward/backward motion. But the back one seems strange so it might actually reverse!
The front motor is different to the rear as it is a 2 speed one.
This is how I think the the rear operates but don't quote me as it could be complete :censored:.

When switched on via the stalk the relay energises in the Bsi for a short time which puts 12 volts on wire 520. the motor operates as the park switch is at 0v. Once the park switch has opened the Bsi relay drops out and returns to 0v. Wire 522 keeps the motor going via some resistors in the Bsi which are being fed by approx 12v. When the park switch hits it's zero position again the motor stops due to it being earthed across its supply lines. The Bsi isn't damaged due to the resistors taking the short.

And if you can follow that you need a medal !:eek:
Reading some other posts about the rear wiper and water leaks, it sounds like the motor mech. is at fault. Apparently there is a plastic gear inside this which strips if the mech. seizes up etc. Personally I would remove the whole unit, see if there is any signs of rust around the spindle and apply 12v to pins 1(-) & 2(+) of the motor connector and see if it moves. It won't park but it will give you an idea what's wrong. alut:

[Modmytop]

Sorry for not replying sooner but been away. Will reply tomorrow.:thumbsup:

Usually it's the mechanism inside the motor gearbox that causes the forward/backward motion. But the back one seems strange so it might actually reverse!
The front motor is different to the rear as it is a 2 speed one.
This is how I think the the rear operates but don't quote me as it could be complete :censored:.

When switched on via the stalk the relay energises in the Bsi for a short time which puts 12 volts on wire 520. the motor operates as the park switch is at 0v. Once the park switch has opened the Bsi relay drops out and returns to 0v. Wire 522 keeps the motor going via some resistors in the Bsi which are being fed by approx 12v. When the park switch hits it's zero position again the motor stops due to it being earthed across its supply lines. The Bsi isn't damaged due to the resistors taking the short.

And if you can follow that you need a medal !:eek:
Reading some other posts about the rear wiper and water leaks, it sounds like the motor mech. is at fault. Apparently there is a plastic gear inside this which strips if the mech. seizes up etc. Personally I would remove the whole unit, see if there is any signs of rust around the spindle and apply 12v to pins 1(-) & 2(+) of the motor connector and see if it moves. It won't park but it will give you an idea what's wrong. alut:

No medal for me then! Not able to look at it right now. But will soon. Thanks again Rustscrat.

[jericlin]

All wiper motors I have worked on have a gear train, a crank and sometimes another another gear train.
The first gear train reduces from rotation speed of motor to useable speed, the crank converts rotary movement to linear movement which either connects to the wiper arm via a pivot or a 1:1 gear train to produce a rotary oscillating movement backwards and forwards to give the required angle of sweep

[Modmytop]

Finally got round to looking at rear wiper. Appears shaft was very tight in tube. Had to strip down. Moving freely again. Tried on car and it seems to work. Not got bolts to fit yet. Took some pics and added a How-To.
http://www.berlingoforum.co.uk/showthread.php?tid=8204

Don't understand why it didn't blow a fuse. ? Will mark as solved. Thanks to all.