M 35BC Electrical draw

[John Langford]

With everything off at the electrical panel, my monitor shows a 6 amp draw when the engine key switch is turned to the first position (engine instrument panel powered up, buzzer out of commission and glow plugs not engaged). Would the panel draw that much or is something else going on? Any suggestions?

[KWKloeber]

John if you rely on the schematic, with key on you would be powering the alarm V+ and (if the oil Sw failed in the closed position) the fuel pump and 1k resistor to ground (0.1 a).  The gauges and lights should be a very low draw.m. Unless I'm missing something not so obvious you should see very low amps. 6a is like one glow plug.

[mainesail]

Depending upon the alternator it could be the field being driven to full field by the alt excite circuit. Clamp the alt feed to test..

[KWKloeber]

John

Sometimes something's right there to smack me in the face and I miss it!  Yes your setup will excite the alt with the key on, whether the oil switch is good or bad. That circuit comes off the hot side of the oil sw (see the schematic.)

http://c34.org/bbs/index.php?action=dlattach;topic=9927.0;attach=8144;image

Rod, how much current might that pull?