has anyone checked the voltage output of their system while running? with/without a load?

Also does anyone with dual alternators know if there is any CEL type of indication if one fails?

 

I haven't tested the voltage output on my truck, honestly never thought of it.

What were you thinking that brought this up? I might be inclined to test mine.


I have the extra heavy duty single alt.

 

im trying to calculate a more accurate amp draw for my lights i will be installing soon. Im currently on travel so i cant go measure system voltage myself. the lights are advertised at 100watts, which at 12 volts is about 8.3amps which is worst case scenario, as the system should not be operating at 12volts, rather more like 14ish... just curious what people are actually seeing tho. if it is at 14 that would be great as 100watts divided by 14 volts would mean the lights are actually only drawing 7.1amps which would leave a comfortable margin for me to put all three lights on one 25amp upfitter/relay

 

also, lets say worst case scenario, im at 12 volts(highly unlikely id say) and the lights are at 8.3 amps... which puts the total current right at 24.9 amps (call it 25), would you be comfortable maxing out a circuit like that or would you think Ford put some safety margins on the power budget. (i dont know what its fused at yet)

 

Tux,
I'd suggest using the upfitter to switch a relay wired (through a Circuit Breaker) to the battery. Minimizing the lenght of wire (and associated voltage drop) should optimize system efficiency. Use a 30 Amp auto reset Circuit Breaker and you'll be covered regardless.

 

Rob thanks. However the upfitter has its own relay and fuse. So i dont see any point to add another relay and circuit breaker. Unless you have another reason im not aware of.

 

Well, you'll love my solution. I just threw a 30amp fuse where the 25 goes so my air compressor won't burn the fuse if it gets worked hard.

Yes, I know, don't do it, I'm not saying its right, but my system has been running every day for almost 2 years now.

I will add, the air compressor also has an in line fuse that has burned twice. It always goes before the up fitter fuse goes. And the up fitter fuse has never blown.

 

With a compressor that sort of makes sense with the variable load being applied. With a few lights at constant power i think i will be good to go.

 

I just had another thought. The charge voltage to the batts should be over 14, but wouldn't the voltage be regulated for the rest of the truck? All the relays and lights and audio, shouldn't the up fitter switches and all be regulated to something like 12.4 or something?

 

Not really as a 12v system is really a 14v system. So components are set to operate usually between 11-15ish

 

update:

I checked system operating voltage with headlights on and fog lights on (not max load, but not min either)

14.1 VDC

I have dual alternators as well (prolly doesnt matter tho)

 

whats the rated output of the xtra heavy duty single alt?

 

I think its 155 amps or so...

 

i just found online the standard is 155 and extra heavy is 200

 

im trying to pick out an amp I think i have my motorcycle sold