Electrical Trouble

[Turboclamp]

Got an intermittent problem. When this problem shows up, heres whats happenning:



1. ) Tachometer quits.

2. ) Stops charging

3. ) Air conditioning compressor quits.



Meanwhile: Still shifts O. K. (automatic)

Cruise still works

Everything else seems O. K.



I cannot get this to happen in my shop, making diagnostics tuff.

Any help would be greatly appreciated.



Thanks,

Ken

 

[Alan Reagan]

I would start with the connector to the ECM. The voltage regulator is there. Guages are controlled from there. I believe the AC is cycled from there. Pull the connector off and make sure the pins are all the way into the connector and locked. Also, pull the cover off the relays and reseat them. From there, I would check the grounds to make sure they are OK.

 

[Dave Fritz]

Ken,



The Engine Speed Sensor is used by the PCM for the tach signal, AC compressor control, and battery charge control. Replace your sensor; it is probably intermittent (they usually just die completely, but intermittent sensors are not uncommon). I don't remember the cost for mine, but I think it is in the neighborhood of $50 from Cummins. The sensor is mounted below the fan and above the harmonic balancer.



Mopar P/N 4746691

Cummins P/N 3924432



The Cummins part is probably less $$.



Dave