You could use the 50amp for pc/audio amp draw..unless your audio is past that yet.
I picked up one of these on Ebay:
It's a 200 Amp current meter & voltmeter, I'm thinking I want to monitor the alternator charging circuit with it. I also ended up with a 50A unit as well by accident (I need to learn to read). I don't think I have a use for it though.
I guess that gets added to the list.....
You could use the 50amp for pc/audio amp draw..unless your audio is past that yet.
@phil - this is what i could find right quick..
OLD SYSTEM (DEAD)
Intel D945GCLF2 Dual Core ATOM
Lilliput 7" 629GL 2008 LED Backlight
BU-353 USB GPS Receiver / iGuidance / IGO8
M2-ATX Power Supply
RideRunner Front End / Various Skins
Windows XP SP3
@ camo.b - I thought of that but just the JL amp alone is fused at 60A, the Kicker amp....well lets say lots more.... I doubt I exceed 50A often but maybe on occasion . I guess I should hook the 200A shunt up to it first just to see.
@ treetop - Thanks Man! I'll check that out and see what I can do with it.
I just wrote on the12volt why ammeters are useless - a voltmeter tells all.
An ammeter for testing or confirming loads & outputs is ok, but they are only temporary.
I know P=IR, I get all that, I have a 2' thick pile of text books in the basement from college reminding me of that.... but I need a voltmeter as Ford gauges suck, and Iwant an ammeter as I am curious what loads I am experiencing in various conditions given the high demand this truck has for current (glow plugs, inverter, audio system, trailer lights, electric brakes, etc.) It might affect my decision on my next alternator. That nice hi-output alternator I showed earlier in my work log has died twice and I am now back to a stock NAPA POS alternator again.
On these trucks the alternator does not kick in for quite some time after starting and the batteries have been beaten down by the GP's & starter, I want to see the result of that too so I think in my instance it may be somewhat useful... but I get what your saying- if all you want to know is "is my electrical system healthy" - voltage will tell you that. What I really would like to use the smaller 50A shunt for is to monitor parasitic draw when the truck is off but I'm not quite sure how I can do that...
Sorry - I may have been misunderstood. I am with you!
IMO a voltmeter is essential - even in a normal vehicle, let alone for us with our non-standard and extra electrics. Many modern vehicles have battery voltage alerts instead since varying voltages only confuse the bulk of drivers. (Hey man, my alternator was overcharging at 14.2V so I set it to 12.0V for my "12V car system".)
I like my digital dash voltmeter 'cos it tells me if the particular alternator I'm running has dropped to lower or float voltage, and just generally to check how it's handling my 500W of lighting and 10A sound system.
But ammeters... They are handy for knowing what your starter consumes (that's one off test - not permanent!) and other things like engine drain, lights, wipers, whatever. And alternator testing is another once off that is done thru its RPM range with a variable resistive load.
But once they are assessed, that's usually it. What good is it? So your lights are consuming 15A - is that good? Is the alternator keeping up?
If your voltmeter (across the battery) shows ~14.2V (for modern charging systems; it used to be 13.8V) then the alternator is fine.
If it's over 14.4V longterm, you're probably cooking your battery. (If it's near or over 16V, you've probably blown a few loads.)
If it's under say 13.5V or 13V, is that 'cos you're idling with big loads, or is the alternator faulty? (EG, worn brushes leads to a gradually dropping voltage under load.)
Anyhow I have covered that ad nauseam on mp3car so I'll leave it at that.
And it's not a power thing (P=VI) - who cares? All you want is the battery to receive its proper voltage and for appropriately sized electrics (alternator vs loads) to achieve that. (That involves driving profile - eg, maybe flattening the battery over 2 hours due to heavy loads, but then enough driving (10 minutes?) with reduced load so the battery recharges sufficiently.)
Re the ammeter shunts, they have no parasitic draw - they are merely another inline resistance. It's only be the meter hanging off that that may draw current.
But why have a shunt anyhow? It's something that is probably weaker than the cable it is attached to; it gets hot but needs insulation (unless in a GND circuit), and it adds to voltage drops. And 2 extra joints that can work loose or get contaminated.
Sure - shunt ammeters are definitely better than the oldskool in-dash inline ammeters, but they stopped using those because they became useless. (Not like the old days where it was more a case of either having generated power else none.)
As to why your truck alternator takes time to kick in, I fail to see why that should occur. I know some manufacturers have weird ideas. Others may have vested interests in battery suppliers.
Most alternators will start straight away. Some may output higher than the usual 14.4V max for a while.
But there is really no reason for a delay. The longer the delay, the more 'strain' is put on the alternator and the worse the fuel economy.
The exception may be if the alternator is too much strain for the cold engine, but I've rarely seen that - even on carbied 1200cc rally cars with way over 500W of lighting.
BTW - most loads can be guessed quite accurately - eg, lights, inverters, etc. Even glow plugs should have their specs. The trickiest is big audio systems because volume is not linearly proportion to power.
I'll have to look back to see what hi-tech alternator you had. If it was some alternator rewound for higher output current then I'm not surprised. Or if it's a Bosch, and - from what I hear - certain GM and other alternators that also seem to have pretty pathetic main power diodes.
Their windings should certainly not burn out. That's a sign of bad design else age (insulation breakdown) etc.
PS - I read back and presume the hi-output alternator you mentioned (the not hi-tech alternator that I misquoted above) is as per your post #70?
If so, despite its apparently heftier housing compared to a stock 105A alternator, if it has been rewound for heavier than its original output then its probably like I said - it will be prone to failure.
That's usually because of thermal issues alone, tho sometimes rebuilders don't upgrade with suitable power diodes.
If the windings burn out, it's a thermal issue. If diodes blow, it can be diode rating & thermal issues. I imagine it can even be changed inductance versus resistance which effects behaviour - especially transient and sub-transient faults (reactance).
I often read of boosted rewound alternators blowing. It makes sense... If the alternator has been boosted because of heavier load demand, it is likely to be operating more often with a higher current output and hence greater heat, but that's in a housing designed to cope with less heat, or shorter "same heat" peaks. Shared diode heatsinking means hotter diodes. Etc etc.
Experienced writers seem to repeat - get an alternator that is designed (ground up) for the intended output. Unfortunately they don't come cheap.
And tho I used to write about not paralleling alternators, now I consider that that may not be so bad - even if there is a mismatch between regulator settings etc. But there I do have quality alternators in mind - those that do not blow because of overloads - ie, they are self limiting - in case one alternator tries to supply the whole load because the other alternator's voltage is set too low. (Of course as the supplying alternator dips voltage due to overload, the other will kick in.) Not that I've analysed seriously, but I've seen a few multi-alternator set ups that seem to work reliably despite no special load sharing circuitry or capability.
Last edited by OldSpark; 04-20-2014 at 08:56 AM. Reason: PS...
Hey Phil, the weather is getting warmer (finally) and I am back to working on my 2014 F350 dually again.
I guess I could look thru your 20 pages of posts to see if the answer is there, but...
I made a console bracket that will hold 4 radios and my 'puter. It will sit on the transmission hump between the front seats. Eventually I will make a box out of diamond plate aluminum that goes over the radios/puter bracket to hide the mess.
I need to figure out the easiest way to get wires to and from that location. The seats have air bags in them, so I don't want to screw around with removing seats.
I don't know if your 2007 is the same as the 2014 or not. On my 2000, the door sill plates screwed in place. When I removed the sill plates there were massive channels for running wires towards the back wall (for antennas and such). I want to run my wires forward of the console, tuck them under the dash, work them over to the door sill channels and go out the back.
The door sill plates on the 2014 don't have screws holding them in place. I was wondering if you had any idea what holds them in place? I heard there are clips and all I have to do is "start prying until they pop off" That sounds like a great plan if one is sure of how to go about doing it.
Sorry Rick, I didn't even see your post until now, not sure why this thread didn't show up in "new posts" for me. Anyways, I did see your question in your work log yesterday and answered there.