6BTA Speed Sensor and Air Heater

[Nicholas Agnew]

Hi Cummins people.  Need some advice on disconnecting original Cummins speed sensors from 1997 6BTA 370HP diamonds.  I need to install new VDO tachos and new single-wire sensors off the flywheels.  Existing tachos take alternator signal and are bouncy.

I want to pull out the old Cummins flywheel speed sensors.  They have two pairs of wires.  One is not connected to anything and the other I assume is for the pre heater controller to sense speed below 950 rpm or so.

1. Is there any other engine alarm/function that the speed sensor is used for on these mechanical engines?  They seem to run fine when I disconnect them completely.  
2. If the pre air heater controller is not getting any speed signal what will it do?  Will it turn on on ignition for seven seconds and then just stay on until up to temp?  My current plan is to wire in a series switch across the relay relay fuse as per other SB advice just for using prior to start.  I find the heaters do help with smoke even in our warm climate.

Any advice would be appreciated.

Nick

Topic

[Tony Athens]

Not to worry about  redoing as you like.  The heater circuit can operate manually as you suggested. Nothing else other than the tach need a speed sensor

[Author]

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