Retro Fit Rain Sensor

[whitenemesis]

New screen fitted today

New rain & light sensor fitted

Aaaargh! Connector is different !!!! Wiring has 4 pin connector, new sensor only has 3 pins

Guessing this is from the fact that my car is right on the change-over from separate rain sensor and light sensor to the combined (and current) rain & light sensor. So is the extra wire I have the separate power feed for the second sensor? MB confirmed my new sensor is correct for my VIN. So do I need a new lead from the upper module to sensor or perhaps MB have an adapter?

Nothing is ever straight forward..... But that's what makes it fun!

Any suggestion / ideas?

 

[television]

If I get time I will look into it

 

[Ellsy Tanners]

I have never heard of a adaptor for a change over.
Not to say it doesnt exsist, but I would say they have looked up and given you the wrong sensor and possible screen to.

 

[whitenemesis]

Don't think so, corruborated by 3 independant sources.

I agree an adaptor sounds unlikely, new connector then!

 

[television]

I have never heard of a adaptor for a change over.
Not to say it doesnt exsist, but I would say they have looked up and given you the wrong sensor and possible screen to.

I cant re call ever reading about any adaptor, the thing does require a live + and - the sensor otput would be the 3rd wire

 

[Ellsy Tanners]

I'll have a look 2mora if i get a chance, but i am not convinced.
Wot are the part numbers on the old and new sensors?

 

[whitenemesis]

So what is the fourth wire????

 

[Ellsy Tanners]

These things are notoreously difficult to get right, and epc errors do happen. if your car is close to a change over that makes mistakes even more possible.

 

[whitenemesis]

New sensor is # A 221 870 88 26

No idea about the old.

VIN is WDB230216....

Thanks for your help

 

[Ellsy Tanners]

Is that 203216?, for wot reason did you have a new sensor in the first place?

 

[television]

Is that 203216?, for wot reason did you have a new sensor in the first place?

It is 203 its not a SL

 

[whitenemesis]

Soz, you're right 203216.

Upgrade! Didn't get auto wipers from new (big mistake).

 

[Ellsy Tanners]

Ahh the plot thickens, didnt read that you are upgrading, just thought you had a fault with the old one!

Well, the loom is almost certain to be different from the ocp to the sensor, thats if your overhead control pannel (dome light ) is capable of supporting a rain sensor.
once sorted you will need to have codings changed in the ocp, front sam, and eis switch to make if function.

 

[television]

The change took place to RLS sensor in 01-06-03 that has 4 pins, the RS has 3 pins

It will need activation in STAR, not easy to work out

 

[whitenemesis]

Coding is sorted once I get the connections right!

A trip to MB for the loom? Or a snip here 'n there?

eis?

 

[Ellsy Tanners]

EIS - electronic ignition switch. It holds most of the cars codings and will have to be adjusted for rain sensor present.

I doubt the loom will be something you can get, you might have to make yourself. i,ll check which pins go to wot and where if i can.
it may come with the entire roof loom, mercs are like that unfortunatly!!

 

[whitenemesis]

I can believe it

Again, thanks for looking into this for me

 

[whitenemesis]

Sensor fitted, new loom fitted wrong connector shell....
Well new connector shell fitted and connected to ocp. No smoke so recon its the right connection. Visited a man with STAR to get things coded. Had tyre pressure monitoring coded ok. Had my Thermotronic upgrade sorted (well no errors). Tried to code rain sensor only to be told it was "open circuit"! Nothing to be done, checked wiring, swapped a couple connections, all read ok but no sensor detected.... Bugger! Must have fried sensor.
Set off home, started raining so put on wipers (#1 setting) and WHAT!! variable intermitant wipe!!! Wipers stopped when the rain stopped, started again when spray from a car hit the screen.......
Seems sensor ok, no malfuction message but also no light sensor function. The car thinks its permanent night.
Spose it could all be "adaption" issues as we didn't get to adapt the sensor to the screen.
A couple of things to think about. Try adapting current sensor then if no luck new sensor. Ho hum!

 

[Ellsy Tanners]

Did your guy with the star, check all the codings in front sam, eis ,and ocp.
if one is wrong it wont work as expected.

 

[whitenemesis]

Did your guy with the star, check all the codings in front sam, eis ,and ocp.
if one is wrong it wont work as expected.

Thanks for the steer, will look into it and report back