12V power consumption

[352F100]

I have a 1999 E-350 Club Wagon with a 7.3L diesel
How much 12V power is consumed by the vehicle when idling and with the air conditioner fan on high?
What are the principal loads on the battery?
Electronic injection?
Heater/air conditioner blower?
Headlights?
How much current is drawn by each load?

[vitalidle]

hmm good question? Could look at each circuit and the fuse for each to get a general idea I suppose.

[Bumpin' Yota]

The only way to know this would be to actually measure with a clamp meter or to use a DMM in series on the circuit to measure the actual amperage "flowing." The fuses on the actual circuits should be quite larger than the actual current "flowing," but the ratings at least get you into the ball park so you dont nuke a DMM if you try to measure current by placing the dmm in series with the circuit.

However it is worth knowing that while the engine is running, it is your alternator that does ALL of the electrical work, until such point that it is over taxed. (For example the truck's systems need 200 ampres of current to run at optimum but the alt can only make 150ampres - this is an overtaxed alternator)

As a result of an overtaxed alt, the voltage will drop down to the batteries' floating voltage (~12.9v - 14.1v pending brand, age, and care.) Once the system's voltage is at or below the batteries' normal floating voltage, the batteries and alternator work in concert to support your truck's electrical needs.

This is why you need a bigger alt if you have headlight dimming issues NOT a capacitor for those with big system. (7.6kW rms system in my toyota... ) Yeah car audio was and still as an obsession/mental illness with me. Who can tell me what flux modulation in the gap is? First one to answer correctly gets a cookie! lol

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Last edited by Bumpin' Yota : 07-18-2007 at 02:04 PM.

[davespark]

[/quote]
This is why you need a bigger alt if you have headlight dimming issues NOT a capacitor for those with big system. (7.6kW rms system in my toyota... ) Yeah car audio was and still as an obsession/mental illness with me. Who can tell me what flux modulation in the gap is? First one to answer correctly gets a cookie! lol[/quote]

(hijack alert)

Since you're talking audio, I'll say that it's modulation (which in this case will likely lead to distortion) of the flux in the gap of the magnetic circuit (from coil through plates and permanent magnet) of a speaker. As current changes in the coil (audio signal) the flux in the circuit changes, which changes the overall coupling characteristics. Gaps are useful for saturation prevention, and unavoidable I suppose for speaker design, but I would guess the dynamic nature of the coupling could be cause for headaches when trying to maintain a clean signal...

So, anyway, I could see it introducing a non-linearity in the coupling, or motor force of a speaker

-dave

[vitalidle]

I don't know my guess would be Flux capacitor!!! Man you guys are talking way over my head!lol

[davespark]

...anything for a cookie