[Northstar John]

Hi Doc: I have an interesting question for you and all the other electronics geniuses. I'm just completing a 37 ford with a Northstar mounted in the rear. I'm using an American Autowire fuse panel and remote operated main disconnect. I'm also using their Lifeline, which goes around the master disconnect to allow current to the ECU, radio, and anything else that has a memory. The lifeline is good for 3 amps, and any more than that will trip the breaker in the lifeline. The remote system is an Auto-loc PL 1800, and the Master Disconnect is controlled thru a relay, (the ground signal from the PL-1800 is not strong enough to actuate the master disconnect). My question is, how can I tell if the Master Disconnect is actuated or not? If you use an LED, as an indicator, it will stay on all the time since it only draws a few MA. If you use a larger bulb, it will simply trip the breaker in the lifeline. When you turn the key on, the dash lights all come on because they draw less than 3 Amps. Any ideas, or a wiring diagram would be greatly appreciated. Thanks. Northstar John

[Holder350]

How about wiring a light into the relay?

[docvette]

Doc here,

How about getting an inductive current meter..just clamps around the output CABLE, shows current being drawn inductively, (on/Off states) , Uses NO current AT all..and I'm sure can be modified to fit into any panel with a little engineering and care..

Doc

[Northstar John]

Hi Guys: Thanks for answering so quickly. I'm not very good at explaining myself. With the "Lifeline" going around the disconnect, it will carry up to 3 amps, (for ECU memory and the like). It will also provide enough power to my remote system that I can actuate the disconnect through the key fob so I can open the doors and windows. Unless I'm mistaken, you should have the same draw whether the disconnect is "On or off", because of the "Lifeline". A light bulb will stay on all the time, so that doesn't help. I'd like to be able to look in my car and be able to tell if the disconnect is on or off. American Autowire says they know of no way to do this, but I can't believe I'm the only guy in town who wants to know the position of his switch. I don't know if this explains my problem any better, but I'll keep trying. Thanks again,
Northstar john

[Holder350]

Why not a Diode setup?

I'll have to think on how to do this......but I think it could be done.

Is the disconnect electonicly controled? if so can you provide a simple wireing diagram?

[docvette]

Originally Posted by Northstar John

Hi Guys: Thanks for answering so quickly. I'm not very good at explaining myself. With the "Lifeline" going around the disconnect, it will carry up to 3 amps, (for ECU memory and the like). It will also provide enough power to my remote system that I can actuate the disconnect through the key fob so I can open the doors and windows. Unless I'm mistaken, you should have the same draw whether the disconnect is "On or off", because of the "Lifeline". A light bulb will stay on all the time, so that doesn't help. I'd like to be able to look in my car and be able to tell if the disconnect is on or off. American Autowire says they know of no way to do this, but I can't believe I'm the only guy in town who wants to know the position of his switch. I don't know if this explains my problem any better, but I'll keep trying. Thanks again,
Northstar john

Doc here,

Sorry bout that..I answered this post once and the post disappeared into cyber~space

What I think your doing is confusing the Master Disconnect contacts with the "Keep Alive " bypass..

The Keep Alive Bypass will provide metered power 24/7/365 to memory, Alarm and poppers REGARDLESS of the State of the MDS (Master Disconnect Solenoid)...On or Off...

The MDS , However will only be powered WHEN the contacts are ON and making connection to the battery, and cable to the starter, and main buss feed (the rest of the car's Electrical system)..and THIS wire will follow the state of the switch..( On/Off)...

This is where you want your indicator lamp to connect..when the switch goes on, the power to the indicator is provided and the lamp lights...When it goes OFF..power from the MDS is removed, thus to the indicator, the lamp goes off..

Should be that simple..


Doc

[ccb]

Just to repeat this. Wire it so, when the disconnect is on (connected) the light is on. When disconnected the light is off.

[docvette]

Originally Posted by ccb

Just to repeat this. Wire it so, when the disconnect is on (connected) the light is on. When disconnected the light is off.

Doc here,

Yup!


Doc

[427v8]

I think It can be done assuming you always have current flow in the system.

Here's the idea:
You need to sense current flow in the keep alive wire. This can be done with a small voltage drop, like 3 diodes in series ( 2 might work better, but figuring that out that would require me to think too much). then put an LED in parallel but backwards with the dodes.

If there is current flow through the system, there will be a voltage drop of ~2.1 volts across the 3 diodes which would be enough for the LED to light up.

With the Master disconnect switched closed you won't get the current through the diodes, so the LED won't turn on.

Important things;

* You need diodes that can handle more than 3 amps.
* you need a resistor in series with the LED to limit current flow.


It looks good on paper!
Keith