Probleme mit Temperatuanzeige und Drehzahlmesser.

[C3Berlin]

Schau mal hier was aus dem US-Forum. 


Der Wiederstand vom Geber nimmt bei steigender Temperatur ab. Wenn Du einen falschen Geber hast, der zu niedrige Ohm-Werte liefert kannst Du diesen auch mit einem Vorwiderstand richtigstellen. Es ist kaum möglich über das Internet einen passenden Geber zu bekommen. Wenn einer für C1 angeboten wird bedeutet das meist nur das er so aussieht und mechanisch passt. Der Ohm-Wert kann völlig falsch sein...…. Ist meist leider so.... 


Gruss aus Berlin 
Uwe 




Hier das der Beitrag: 
     


Temperature Sending Unit
 

A common problem with our C1s is a faulty or improperly reading water temperature gauge.  You know the problem – the gauge reads that the car is overheating, but all indications are that the temperature is actually normal.  While you can have a bad gauge, the problem is normally associated with the sending unit screwed into the manifold water passage.

 

The current GM replacement sender is available (GM p/n 12334869).  It replaced the original GM sender (p/n 1513321) and while it looks right it does not provide the proper resistance to the water temperature gauge circuit.

 

A common quick fix is to add a resistor in series with the sender, with a little experimentation you can get the gauge to read correctly – however, the gauge will read correctly only at the one temperature where the resistance is exactly correct for the gauge.

 

To verify that the problem is the sender and not the gauge, you need to remove the sender from the car and suspend it in a pan of water on the stove.  Use a cooking thermometer to monitor the actual temperature of the water as you raise the temperature.  As the water heats up, using an ohmmeter you can read the resistance from the center connection of the sender to the outside brass portion of the sender (where the threads are).  A properly operating sender should indicate resistance readings very similar to these:

 
220 degrees = 70 ohms
200 degrees = 90 ohms
160 degrees = 140 ohms
120 degrees = 250 ohms
100 degrees = 340 ohms
68 degrees = 638 ohms