Easy Access Switched Ignition Source QSB6.7

[Paul Greenhalgh]

I need to connect an external device needing only a micro current draw to a switched source of power….ideally on-engine with easy access, rather than somewhere off-engine (like the ignition switch itself).

On my QSB 6.7 480, is the easiest-to-access switched power point the oil pressure switch?

 

thanks in advance

Topic

[Tony Athens]

Your specificially said you wanted a swithed power source that could supply “micro-amps” od current..   

Now you want  a “signal” measuring in millivolts??  

I offered help but I do not think you have your end under control as  nothing about a finding a   “signal” ( what ever that is?) that you could measure in a few “millivolts” has anything to do with a switched power source.  

Voltage & current–Do you really know the difference?

A drawing ?

Maybe someone else can sort you out ?

 

[Paul Greenhalgh]

Thanks Tony.  I just need a signal….a few millivolts….it doesn’t even need to be a full 12V, >8.5V will do,  on the ignition circuit.  Maybe I could even pick up from the 22SI alt?  Just trying to find an easy and safe connection point.

[Tony Athens]

Swithched power CANNOT come from an  existing oil pressure switch  that is part of your alarm system..

Make a simple drawing of exactly what your are trying do or accomplish.  Drawing 50-100 milliamps from your ign – key on circuit is OK if done correctly 

[pwrobert]

On my boat I was long ago told to not have anything directly connected to the key switch – just power- run circuit and start wire. The Run circuit has many wires connected to it Indirectly. The Run wire from the key switch goes directly to a solenoid and fuse holder with 8-10 fuses of different ratings. Anything that needs to be On when the Ignition is On comes off this fuse panel. Actually the starboard key switch has its own solenoid and fuse panel. Things like synchronizer, exhaust temp sensors and gauges, instrument lights, etc all have their own fuse. No gaggle if wires off the key switch. No devices piggybacked off another device w

hich only causes multiple diagnostic problems. <br />simple setup. Install solenoid, run power wire to one side , one ground wire, wire from key switch and the outgoing power wire to the new fuse panel. 

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