460 electrical issues advice please (Rear fog lights, Reversing lights, Front wipers)

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John757
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Hi all

I was getting set to take my G for an MOT and thought id check the lights... found reversing lights not working, and rear fog light ...

1. Reversing lamps (were working a while ago) have cleaned all connections in rear lenses/wires etc, and bulb holders..fuses,  changed bulbs , seated correctly ...nothing.. where is the reversing lamp switch located please?(autobox)

2. Rear fog light.dead. changed bulb, checked fuses, cleaned connections (were a little rusty) checked connector inside door, cleaned it .. still nothing... looked at switch which illuminated when pulled out... (front fogs and all other lights working ok)  pulled out switch no loose connections... what's wrong with it?

Wipers started stopping in all sorts of random placed today also (i dont think she wants an MOT!!)  the wipers stop in the middle of the windscreen when you turn them off... is the relay the likely cause (does it park them ?) where do i find it in the car...please?

 

i spent all day trying to fix the problems... very tired...need a beer... please if someone can point me in the right direction...im usually quite savvy when things stop working...

 

John

 

 

mgrays
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Re: 460 electrical issues advice please (Rear fog lights, ...

Foglights is likely the wiring as it comes from body to door. Not a 5 minute job to do properly.

Reversing switch on a manual is under the rubber gearstick gaiter.. would guess auto would be similiar

Wipers only park when ignition is on.. well on a 460, it is when they do not park you have a broken track inside the wiper motor.

needamerc
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Re: 460 electrical issues advice please (Rear fog lights, ...

Reverse light switch on a W460 Auto is on the gearbox. It is a combination switch that also controls the safety lock out for starting in P or N only. One function can work while the other doesn't, so you will probably have to change the switch.  A common fault. Easy enough to replace. New MB part only.

Wiper relay is under the dash, above the fuse box. Difficult to get at. There are usually two, second one for rear windscreen. Also common fault.

Rear fog is a PITA. Can be wiring within (or going to ) the rear door.

Also expect millions of earthing issues.

gav.helme
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Re: 460 electrical issues advice please (Rear fog lights, ...

John

Did these all happen at once or over a period of time?

Two main large Earth connections

One under the right dash area on the inner A pillar up behind the fuse / relay board

Other on the rear of the chassis, left i think under the rear bumper area

Two big clusters you can't miss, both prone to issues

Good clean and re attach

Make sure you clean off ALL the rust, paint and debris etc from both chassis / body and each terminal ring

A little Vasoline may help also

Gav

John757
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Re: 460 electrical issues advice please (Rear fog lights, ...

thanks for the replies guys...

anyone got a picture of the reversing light switch?

exact location under the car?

(quoted £27 for new switch at MB- special order)

I cant say for sure when the fog light stopped working...assumed it did still work as the tell tale light comes on (despite the fog not coming on) may run a new supply wire to it... tried re-earthing it... nothing... circuit tester says 1v at the bulb holder (bulb works fine)

reversing lights within last month... swapped out a bulb when i only had one on... both then worked...

wipers happened yesterday...after i was in the dash and fusebox trying to sort the other issues... probabily knocked something loose re the wipers... am just checking now..

MOT due end of month... :(

MB cant work out which wiper relay i need....anyone help please... there are a few in there that are all different sizes.. they need a part number from me!!

 

John757
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Re: 460 electrical issues advice please (Rear fog lights, ...

i took out the wiper relay and my front wipers still come on ... is that normal? is the relay only for the intermittent and parking of the blades?  seems i have two relays removing each made no difference to the wipers..... front or rear....

 

the intermittent does not work... and they stop as soon as you turn them off... in the exact part of the sweep they are in...

is it something other than the relay?

i'm stumped.... problem occurred after a wire was connected to the circuit board onto a spare lead...(attempting to cure a different problem- now fixed) wipers would not turn off... removed wire.. wipers turn on and off on stalk but do not park , run constantly on intermittent setting (worked perfectly up to that point.. obviously there was an overload on a circuit... wipers now not working correctly.... i thought the relay switched them on and off.... if not what does it do? 

 

John

g wagon g
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Re: 460 electrical issues advice please (Rear fog lights, ...

Hi

There is a track of copper on almost all wiper motors. When it has done one full revolution inside motor the track stops and so should the motor and wiper arms

Mine is a bit worn and they slightly overpass the park position and sit up the screen about 1 inch further than the normal park position

 

John757
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Re: 460 electrical issues advice please (Rear fog lights, ...
Ok thanks What makes the intermittent wiper function work?
g wagon g
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Re: 460 electrical issues advice please (Rear fog lights, ...

A timer relay. this is usually a bi metal strip like on your kettle at home. When it gets to a click off point it resets. Some are transistor controlled and some now are digitally controlled

This gives you a time signal

There are different versions and i think g wagons are perhaps a timer relay

Either way there is an intermittent relay to set intervals of wipe

There are many different sorts but i think the g wagons have the ones i have said. I might be wrong but im sure there is a relay to control this operation

Others might tell me different

                                           G

John757
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Re: 460 electrical issues FIXED (Rear fog lights, ...

My reversing lights are now fixed... i spent a lot of time with a circuit tester... looking at the possible causes... including testing the power feeds in and out of the switch which on mine is under the car as its an auto... my fault turned out to be a broken block connector inside the car under the dash near the centre console where a wire had pulled itself out... (red and white wire)... the power for the reversing lights comes from sharing power with the front wiper motor... where the wires plug into the bottom of the motor housing in the engine bay next to the battery you will see red and white wires, its worth checking this as well....

fog lights fault took a lot of testing wires etc... until i found the main light switch wasn't putting out current when switched to rear fog... switch now replaced..all working again.

front wiper problem was just a burnt out relay... replaced it and now my wipers park correctly and have intermittent again. went for MOT today.. passed with flying colours...no advisories...and the tester said it was the first G he had seen without any rust!!

.. finally have my G in good working order. my new Clarke multi-meter has paid for itself ..by me not changing parts that were not faulty... plus i learned where a few more bits are for my G! Appreciated all the advice from you guys... John

LEONIDAS
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Re: 460 electrical issues advice please (Rear fog lights, ...

Hi Gav,

Good advice as always.  WD40 shorts out many electrical problems, but what about using a multimeter to check continuities and earths???