outside air temp sensor/mfa problem

[davidwort 0]

it reads -40 deg

 

so i search the forum, and it looks like i may have a duff/shorted sensor

 

pull sensor off and check resistance across it, it seems OK and the resistance value changes as I blow warm breath over it :scratch:

 

OK I'll check continuity then... the brown/white(or maybe brown red - can't remember already) which I assume is the feed back to the MFA from the sensor is a good earth, slight potential difference to battery -ve but same as wiper motor etc

 

I check the feed wire (red/white or what ever it is) and get + 0.2 to + 0.35 Volts with ignition on :scratch:

 

I've no idea what to do next, bridging the terminals just leaves the mfa at -40

 

any ideas?

[davidwort 0]

OK, this morning it's back to normal, what's that all about? :shrug:

[A-J 0]

I hate intermittent faults! Mine reads -40 but I know thats because the sensor fell off.

[g60karmann 0]

has anyone lost the outdoor temp reading from the MFA all together? I don't even get the selection when I cycle through!

 

but then again it's not exactly important, just reach your arm out the window... oh its wet n cold

[sparks 0]

yes me

my mfa misses the whole outside temp thing altogethier ive been told that if your sensor is there but broken it reads -40 if it not there at all then it misses it out on the selection

 

cheers stu...