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Old 11-12-2021, 10:02 PM   #21
142 guy
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Join Date: May 2014
Location: Saskatchewan, Canada

The CAS ground carries DC power for the sensor in addition to the ground path for the cam and tach signal. Given that the sensor does not draw a lot of current, connecting the sensor ground to pin 1 is not a huge issue. When I did my set up, I ran the sensor ground directly to the common ground point on the motor. Since you are using the original B20 intake manifold there is a bolt on top of the manifold towards the back that was the common ground for the D jet system. That is what I used for the sensor ground and the ground connection for the controller (DB37 pins 15 - 19). If the CAS had a separate signal ground connection I would have run them to DB37 pin 1; but, it doesn't. Either option will work because the CAS sensor draws very little current and causes very little ground potential rise in the controller ground plane relative to the engine ground.

10.8 volts during cranking should be no problem for the CAS. I run a battery in the trunk in my 142 and the supply voltage during cranking drops to about 10.5 volts because of battery internal resistance and the long run from the trunk to the engine compartment. It has never presented a problem for the CAS.

Last edited by 142 guy; 11-12-2021 at 10:17 PM..
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