Nokia Car Kit HFU2 - Mic not working

[ETAF]

Hi,
I have a Vauxhall Zafira with a Car Kit for a Nokia 6310i phone

The sound comes via the Radio , using a HFU2 control box

And the Mic works OK on the phone - BUT not on the car kit
I removed all the HFU2 connections and the Mic worked OK
for a day only

Now its not working - BUT only on the Car Kit
I purchased a new HFU2 control box
and fitted but still have the same issue

I'm trying to get hold of a microphone to test

Anyone any ideas what the problem may be
or indeed how its wired

Does the Mic use the phone or Cradle at all

From What I can guess
is the phone when in the cradle - lets the control box HFU2 thats its connected
and then the mic part just uses the car Mic which is wired into the HFU2 control box directly

Any thoughts

Thanks

 

[Belle427]

Normally the microphone should be wired directly back to the control module and plugged in, ive not seen many of these but the ones i have do not connect to the cradle.
I would consider taking out the microphone and examining the cable, not a nice job on some cars but rushed installation methods can see the cable damaged.
You may be able to find a compatible microphone on ebay and just plug it in temporarily to test it.

 

[ETAF]

Thanks for your reply
I have found some more info on the web and see that the Mic is connected directly to the control box as you say
Further testing , i seemed to get a noise from the cradle
I call the mobile on a landline and I can then tap on the phone and hear that noise and myself very faintly - I'm not sure how the cradle mutes the actual handset
From a circuit diagram appears to use pin 8 and 9 on the cradle
so i assume the mic is somehow switched off on the phone ????
anyway
So my plan today
is
1) try connected the mic in to a Laptop and see if i can record from it - and at least test if that works
2) And also try a mic from a headphone combination thats used in a PC and see if that works
3) Play around with the cradle and see what I can do with that - all the pins appear to be sprung still

maybe its the actual handset itself ............

Thanks again

 

[Belle427]

Its worth checking the cleanliness of the handset pins etc but apart from that i dont know what else to suggest apart from trying a spare phone.

 

[ETAF]

Thanks
Now have another issue - the footwell full of water this morning - as my wife went out in the car, she just called

So i will have look when she gets back at the heater matrix - i dont think I did anything - BUT I suspect the pipework comes through that area for the heater - so i may have dislodged a pipe - but would have noticed if i had to force anything back - and I didnt
But it rained heavy last night - so I will have to have a look a little later today and see what i may have done or whats blocked

Oh dear ......

 

[ETAF]

took everthing apart - even the cradle and re-seated all connections and wires
Got the thing working
unfortunaelty the water damaged the old HFU2 unit
so i put that elesewhere in the car
and then cleaned out all the drains throughout the car
hopefully no more water will get in

thanks for any help