Electrics: Cabin Temp Sensor

[grrr]

Originally Posted by dantherman

Cleaned out the small grill in the car that was full of dust for the climate control but I didn't know that there was a small copper wire in there that I've bust
How do I fix it can it just be resoldered?
Oh boy..........help!!!

just ordered a second hand complete heater panel, are they easy to swap or will it need re programing etc?

I did the exact same thing, pulled the whole thing out while removing what I thought was a dust bunny.

The safest option is to resolder the thermistor from the other panel you bought - or get a new thermistor for a few bucks like described several times in this thread. That is what I will do.

[Bluesea]

Originally Posted by bigtree

Well all done and back in the car and no CCM DTC

Really pleased with this fix, now if i could just get the trim on the door/window to stay stuck down!!!!

Thanks chb, Rob and Mike for the information and help, i will post again with some more info, i have taken some temperature measurements and will post these with a few tips for anyone else.

I have a spare thermister too if anyone wants it, cost £5.15 + postage, if not i will drop it back to RS.

Hi BIGTREE,
If you still have the 'spare' Thermistor I would be very grateful if you could let me know how much I need to send to you for you to mail it to me ASAP.
Many thanks in anticipation,
Bluesea

[Funky Diver]

Bluesea, not sure if you got sorted but this is the kinda thing you need...

10k Thermistor on eBay

And a quick buying guide, some key words, these things are available everywhere if you need one.

NTC - Negative Temperature Coefficient. Thermistors are Thermo (temperature) Resistors. The ones you need lower their resistance the warmer they get.

10k or 10k Ohm - this is the value of the resistance at (generally) 25 degrees centigrade. Obviously the cooler the thermistor the greater the resistance, which makes them REALLY difficult to test to see if they are working or not.

3% 5% - this value reprresents it's manufactured accuracy at the stated temperature. Don't worry about it, it won't really make a great deal of difference for our use. For example, a 10% accuracy will produce a +/- 1k Ohm difference in measurement, which'll translate to about a 1 degree celcius difference in heat. Will you really notice the difference?


Final point, just make sure you're buying one with legs on, and not a little block style. The legs you will need

[Chrismmoore]

Pull the console out and up with a bit of wriggling. I did my S60 today, a bit of advice to avoid airbag service alarms..... disconnect your battery!! Soldering the new tiny resister back in is tricky if you are near 50 or older as you need close eyesight and a very steady hand(s), I had to get my younger wife to slip the tiny wire into the tiny solder filed hole

[jpgriffith]

Originally Posted by chb

Just a few small points for future fixers:
I disconnected the battery and then with key in ignition turned to position two I moved the gear selector all the way back to gain access.
As said above, make sure you remove the correct two torx screws. The whole central unit lifts out easily with no clips. It is quite heavy!
I unclipped all the cables from the unit to allow me to work on it out of the car. There are no duplicate cable, so no chance of getting conectors mixed up.
The unit you have removed consists of a central frame with the radio unit and central unit sitting inside it.
Undo the four torx bolts (not 3) and then release the four clips (two on each side) to release the radio from the carrier frame. The unit with the climate controls will then separate with no force from the radio bit.

Access to the thermistor is from the rear. Undo all the silver philips screws and unclip the plastic covers to gain access to the circuit board.
Be brave, the circuit board just pulls away, it's a friction fit with no clips.
You are then at the thermistor!
Solder in a new one and reassemble everything in reverse.
Easy really. I love working on Volvos, good quality materials and logically designed to come apart.

Your details kept me from wasting a lot of time wondering how to get to the thermistor and wondering whether or not I was going to break something along the way. Thanks for paving the way to a successful repair--very satisfying!