Rear wiper electrical

Hi all,

Landy: 110, 200Tdi, 1992

Spent 6 hours yesterday taking apart, de-seizing, greasing and reassembling my rear wiper motor yesterday.

Before installation I tested the motor on a separate 12V battery and it worked fine (to my surprise), but when I installed it back onto the rear door and connected the electrics, nothing worked at all, no whirring, nothing.

I checked to see if the motor was receiving power (with ignition on and rear wiper knob on) and there was 12.5V on the green/red, which I believe is the main power source, but even though there was power the motor still wasn't functioning.

Could the unit be receiving too little power?

Is the some sort of relay elsewhere that I'm not aware of?

Why are there 4 wires going into the motor? Green/red = power, black = earth, then there's green/brown and green. The latter two are connected to a switch on the motor that is activated/deactivated as the cog turns.

Many thanks

park switch
check earths first then
bulk head connector and loom as it enters and exits drivers side chassis leg

it is also common for wires in this loom to rub through internally or behind rear lights.

fanatic said:

park switch
check earths first then
bulk head connector and loom as it enters and exits drivers side chassis leg

it is also common for wires in this loom to rub through internally or behind rear lights.

Click to expand...

Thanks fanatic, but what are you referring to when you mention 'park switch'?

When you turn off the switch in the cab the wiper keeps going until it "parks"(stops).

666 george said:

When you turn off the switch in the cab the wiper keeps going until it "parks"(stops).

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Thanks George, that makes sense to me now. Any idea where I might find the park switch? I'm sure it won't be located at the rear because there are only wires behind the casings there.

Anyone know which one of the following circuit setups is true for the rear wiper:

1) Power to rear wiper knob, rear wiper knob to fusebox, fusebox to rear wiper motor.
2) Power to fusebox, fusebox to rear wiper knob, rear wiper knob to rear wiper motor.

I imagine it's option 1?

1

park switch will be part of wiper mechanism, it is fed by permanent live on say a 1990 model and causes wiper to park when switched off

fanatic said:

park switch will be part of wiper mechanism, it is fed by permanent live on say a 1990 model and causes wiper to park when switched off

Click to expand...

Yup, found it. As a matter of fact I ended up disassembling and cleaning it yesterday but didn't realise what it was until now. Should be working fine, so it must be a matter of low amperage (possibly a chaffed wire) going to the rear wiper motor's main feed.

Might run a bypass once I find out which colour wire to test.

drewster said:

1

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Drewster, would you happen to know what colour wire comes from the fusebox and heads towards the rear? I'm fault finding with a multi-meter you see.

Many thanks

get a copy of Rave - it will help yu immensely

Tried the RAVE CD's for my 1992 110, but the diagrams are confusing to read and my Landy has probably been butchered to such an extent that the diagrams may just add to the confusion.

Back to the old fashioned way of tracing with a multi-meter.

Fixed it! In case anyone was wondering, here's how I figure the historical failure occurred (might be useful for someone with a 1992 Landy with a similar rear wiper problem):

Regarding the 4-pin white plastic connector block, located behind the rear panel: some of the pins were corroded or not making contact, which I discovered when I accidentally did a wiggle test and the motor burst into life (realising I wouldn't have to spend hours tracing a wiring fault with a multi-meter, I yelped like a little girl). So, I cut the block off completely and replaced each break in the wire with insulated spade connectors.

One of the previous owners must have lost interest in tracing the problem, so because the wiper was not in use, it seized. Before finding the electrical fault I'd already unseized and serviced the motor anyway.

Hope that helps someone.

Now I just have to figure out why the rear squirter isn't receiving power. At first glance it seems that the squirter live wire is missing from the plastic connector block mentioned above. How do I test to see which one of the spare wires behind the offside rear panel is for the squirter power?

Bloody previous owners.

I think the pump for the rear squirted is located on the side of the washer bottle under the bonnet rather than at the back

davethsparky said:

I think the pump for the rear squirted is located on the side of the washer bottle under the bonnet rather than at the back

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I have a strange setup that one of the previous owners must have been responsible for:

On the safari door there is a squirter pump attached to the water jacket. But also there's a second pump attached to the washer bottle under the bonnet. I believe the under-bonnet pump was abandoned years ago and someone installed the safari door pump instead. Why they did this, I don't know.

I just need to figure out where the live feed for the safari door pump is in the mess of wiring behind the rear panel, if it's there at all. I know the rear pump was working at some point because someone drilled a hole into the safari frame, piercing the water pipe in the process, causing the frame to rot at the bottom right hand corner. They must have been using it for ages until they noticed because the frame was very rotten in that spot.

I repeat, bloody previous Landy owners