external temp sensor replacement (A guide)

[Scimitar]

..... In progress.

I've noticed that the question has been asked alot, but the answer is usually the same.... "This has been talked about alot just use the search". The problem I've found is that when discussed in the past people say to just unscrew the bolt on the bottom of the mirror, take the plastic off and re-solder. A few questions come to mind here, which piece of plastic do you take off and which way do you pull it? I've read some people saying to prise it off with a screw driver others saying it will slide off if pulled towards you (though not mention where you are ). Hopefully this thread can stop the questions being asked over and over

I'm going to have a crack at this myself and make a guide with photos "a picture is worth a thousand words", but if anyone wants to contribute then please be my guest.

So here we are at the beginning. I'm assuming the plastic to be removed is the blue piece... With these pictures as an aid, does anyone want to hint on the direction I need to attack it?

Scim

 

[cupramillo]

Looking forward to seeing the rest of this. Need to get mine done in the future

 

[markmeus]

Yup unscrew the screw and the blue plastic mirror cap should come off with some persuasion.

 

[PhilW]

Added to FAQ thread.

 

[garyh370]

I have just tackled mine and i unscrewed to screw at the bottom as pictured!! then i removed the black plastic piece not the colour coded cover! With abit of nice tugging. Then instead of re-soldering the new sensor on main reason because i don't own one i cut the wires going the sensor at the bottom leaving plenty of room to rewire!! Then rewired the sensor piece back on job done

 

[markmeus]

Guess I did mine the hard way then.

 

[slim2005]

Did mine last Sunday. Undid the screw on the bottom and then carefully with a screwdriver, went round the bottom of the coloured bit and it popped off.

Removed the door card (bought a trim removal tool, which meant I didn't break any of the plastic plugs)

Removed the black plastic connector off the new temperature sensor.

Pushed a coat hanger through next to the wiring going into the mirror and then pulled the new temp sensor cable through into the car.

Cut old temp sensor in mirror and pulled brown and black wire out of wiring loom.

Connected up new sensor cables and heat shrunk for extra protection over connections

Replaced door card

Job done

 

[Robbie C]

Nice one, I'll be doing mine over the next couple of weeks so will add some pics

 

[A.m.C_Ibiza1]

when you do it its about an hour easier to cut the wires! thats the way i did it and many others and it does the same job!! Good lick

 

[Scimitar]

Hi guys, great to see so many responses

I'm going to have a go at it next weekend with any luck. Seems (as I expected), there are many ways of doing this

 

[lemonslap]

as said above I just cut the wires on mine and soldered them then made sure they were well insulated after, has been like it for 3 years now no problems

 

[Scimitar]

Hi all, sorry for the delay, I didn't forget, just alot on at the moment!

Anyway, i did it so here are the pix and description as promised!

Here we go:

Basically i levered around the lower black part you can see has been removed in the picture above (Don't forget to remove the screw!). My advice is to get a screwdriver in and make a small gap. At this point you can see the clips which are holding this piece in place. With another screwdriver it is possible to push these clips in to painlessly take the piece off as shown. (There are only two as you can see in the pic, and there is still a bit of a crack as you pull it off, but just go with it)

Here you can see I have spliced on the new component:

I cut the wires staggered by 1cm to make sure there was no chance of the splicings making contact. I cleaned the wires with a fibreglass pencil and IPA then covered the connections in nail varnish to seal them. Then i added heat shrink (as pictured (don't forget to put this on before hand)) and covered each end and the whole temp sensor in non setting silicon gel for waterproofing.

At this point I discovered that the temp was now reading -5 rather than the usual -50. Better than usual, but not idea. So i proceeded to remove the door panel where I discovered the main connector had become corroded. After some cleaning with IPA and switch cleaner with cotton buds etc it was all sorted:

I've read elsewhere on the forum about people changing the sensor and this happening and this is what I found fixed the problem.

Also before adding the new sensor i stuck a potentiometer on the bare cabled to find out what resistances equated to what temperatures on the head unit so rather than spending £20 in future I can purchase a thermister from where ever for 20p instead which will do the same job

Hope that helps

Scim

PS, getting it all back together is alot harder than taking it apart!

 

[makso]

Please tell us what are the values of resistances. I found on some Russsian forum that you need NTC thermistor wih these values:
R25=1500 Om
Working points:
R100= 105-110 Om
R0 = 4650-4750 Om
It would be nice to compare these values with the ones that you mesured.

 

[sibiza]

Hi, old topic, but anyways...

Could you please tell us, what data did you discover with potenciometer?

I'm tired of swapping these expensive sensors also.

Thx.