French electrickery

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Derekofpriory
Posts: 33
Joined: 16 Jan 2011, 16:23
Location: Essex
My Cars:

Post by Derekofpriory »

Hi all,
I think I am making progress, I have continuity from sensor to the plug on the inner wing. Today I removed the inner wing shields to get to the wires coming from the socket. By putting a sewing machine needle in a connector block and multimeter probe in the other side I pierced the insulation of each wire in turn but was unable to find a wire that was connected to the sensor. Therefore an open circuit puts the fans on hign speed by default and I assume triggers the light on the dash. Here comes the but, does anyone have any tricks to fix this, the socket looks to be moulded on, otherwise I will get another socket from a breakers and solder each wire in turn and insulate.

Cheers Derek B.
our car spent Friday afternoon and Monday morning in the electrics area of the Factory!!
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

Hi Derek,

Still only me ? :roll:

I also found my break with a needle and probe, and soldered a bypass wire around the connector.
That wasn’t too difficult because the plug had a sliding latch.
You may have to make a small drilling and pass a wire through the inner wing.
Resoldering all wires onto a new connector is a fiddly job that can go very wrong.
2002 C5 2.0i AL4 230,000 km 76372389
Derekofpriory
Posts: 33
Joined: 16 Jan 2011, 16:23
Location: Essex
My Cars:

Post by Derekofpriory »

Hi Clogzz,
Thanks for the tip, I would have thought that after 20 years working for the R.E.M.E. I could have thought of that myself, - work smarter not harder. :oops:
Any way, problem solved :D :D :D, no fans on start up, temp gauge working and no flashing lights, I didn't get chance to check low speed status, bad light stopped play. Thanks again for all your help, and if anyone wants to know I have recorded impedance readings for the blue sensor, they are not exactly what I would have expected:
Terminal 1 to Terminal 2 (the thermistor) From fridge, 9k Ohms; Room temp, 5k Ohms; Hot water, 1k Ohm.
Terminal 3 to Body (High speed switch?) From fridge, 4.2k Ohms; Room temp, 3.5k Ohms; Hot water, 1.6k Ohm.
The switch impedance figures seem high to me because I expected a switch and for it to be either open or short, the current going through the temp dependant resistor would not be sufficient to operate a relay if that is how it was supposed to work. :? :?
Airbag light, that should be the connector under the seat, and lack of driver rear door electric windows, that should be broken wires where they go from pillar to door, and that should be the end of our electrickery niggles for a little while \:D/
our car spent Friday afternoon and Monday morning in the electrics area of the Factory!!
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

Hi Derek,

You’re welcome, and thank you for the interesting thermistor readings. :)
This blue sensor is then a NTC, decreasing in resistance with rising temperature, but nothing to operate relays.
I trust that you’ll celebrate with a couple of Hens in your allotment. :lol:
2002 C5 2.0i AL4 230,000 km 76372389
Post Reply