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Pre-'93 wiring

I need to tap some power from the fuse panel that will be live all the time except when cranking. I know that wipers, headlights, rear window deferoster, etc. have their power cut off while cranking the engine, but they only are live when the vehicle is on. Is there anything that is live all the time except when cranking? How about one more: is there anything that that is live when the vehicle is on, INCLUDING while cranking?

I won't go into details of why I'm looking for these things, but suffice it to say that I have a few things to hook up, and knowing these things will be very helpful. I also don't think it matters which model, as it seems that this is a feature that would apply to most water cooleds (I said up to '93 because those are the ones I'm most familiar with, and I don't know if much changed with the wiring after that.)

Thanks

Reply to
Ed
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How many amps circuit do you need?

Reply to
Woodchuck

You didn't tell us what car, but the wiring is pretty uniform in this regard. What you are looking for does not exist, but can easily be made. Get a normal, SPDT automotive relay. They have 5 terminals, numbered 30,

85, 86, 87 and 87a.

Connect number 85 to ground, 86 to the start wire from the ignition switch (the one that goes to the starter solenoid), 87a directly to the battery and finally 30 to whatever load you have that needs constant voltage except while cranking. The relay coil will draw a very small amount of current while cranking, but no current at any other time. No chance of the relay draining your battery.

Yes, plenty of things have power even while cranking. Check the wiring schematic for details, but one obvious place would be the positive side of the ignition coil primary.

Reply to
Randolph

For completeness I should add that a fuse would be required, as close as possible to the point where you tap into battery voltage.

Reply to
Randolph

Reply to
Rob Guenther

What I meant to say here, is that I'm looking for some source that ONLY is live while the vehicle is on, INCLUDING while cranking. In other words, this would not go through the load reduction relay, right, but would also go through the ignition switch?

Ed

Reply to
Ed

Plenty of places. Ignition coil primary (positive side) is on whenever the ignition is on, cranking or not.

Reply to
Randolph

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