[GordMay]

Testing Pressure Guages
Excerpted from a guide posted on the Cruisers Forum: http://cruisersforum.com/index.php?referredid=79
under the thread: com/showthread.php?s=&threadid=645&highlight=gauges+in struments

...
Pressure Gauges:

1. Disconnect Dark Blue Sender Wire from Gauge, and turn power ON.
The Pressure Gauge should read ZERO Scale (Low Pressure).

2. Short the Gauge Sender Terminal to Ground.
The Gauge should deflect to FULL Scale (>High Pressure).

3. Measure Resistance from Dark Blue Sender Wire to Ground.
American Press. Sender: 240 Ohms (Zero Pressure) 33.5 Ohms (Full Pressure @ 80 psi)
European Press. Sender: 10 Ohms (Zero Press.) & 180 Ohms (Full Press. @ 150 Bar)

See 4, 5, & 6 above (but Dk. Blue Wire)
4. Disconnect Dk Blue Wire from Sender on Engine Block.

5. Test continuity of Dk. Blue Wire.
Zero Ohms from Block End to Gauge End - If not, repair or replace Wire.


6. Measure Resistance from Sender Terminal (on Block) to Ground on Block.
Should read as per (3) above - If not, replace Sender.


HTH
Gord