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Discussion Starter · #1 ·
I'm giving my electrical system a fairly detailed check as I plan to upgrade my FICM in the near future:

I had the Motorcraft 850 batteries that are 39 months old checked today, they are still good for a while.

I have removed the 3 year old NAPA alternator and will be taking it in to have it bench tested tomorrow.

I decided to look at parasitic draw today before reconnecting the batteries. So I left the DS battery clamps unhooked from the battery, connected the ground on the PS and passed my 10A ammeter through the positive terminal.

With the red 6 gauge (or whatever it is) main feed wire not connected to the battery clamp on the DS, draw was at 0.

Connecting the red main feed wire back to the battery clamp, draw went to 2.1 AMPS.

After waiting for the interior lights to go off in 30 sec or whatever the time was, the current draw dropped to .5 AMPS.

After connecting all of my aftermarket power wires, the draw went up to .65 AMPS, I'm guessing the majority of the increase was from the alarm system.

So my question is to those of you that have checked this:

Does this seem in line with your findings?

Does anyone know what the Ford spec range is on this?

At least I now know that a little solar charger should be capable of at least 1 AMP. The truck sits for days, even weeks occasionally so I think this would be a good investment, it will save me having to connect the charger to it after it has been sitting for a while.
 

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After waiting for the interior lights to go off in 30 sec or whatever the time was, the current draw dropped to .5 AMPS.

After connecting all of my aftermarket power wires, the draw went up to .65 AMPS, I'm guessing the majority of the increase was from the alarm system.

So my question is to those of you that have checked this:

Does this seem in line with your findings?

Does anyone know what the Ford spec range is on this?
For 7.3L's the amp draw for the modules is 50 mA or less. Or 0.05A. Your 6.0L should be the same.
The proper procedure is to connect your ammeter in line with one battery while the other is connected, then disconnect the other battery after the modules have gone to sleep. I think your amp draw is excessive. I would expect that a good alarm system would draw about the 0.15A that you saw as a difference. But your baseline draw without your extra stuff of 1/2A sounds too high.
 

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Discussion Starter · #4 ·
The 1-2 amps was right after I made the connection so it lit up the interior lights. The 50mA was after the dome/cargo lights went off and likely the module went to sleep so it sounds like I am inline. I just didn't start with a connected battery first so that's what woke up the module and turned the lights on, correct? If I had done it the other way around (the recommended way), the module would have stayed off I expect and I would have got the correct reading of 50mA immediately of the 1-2 amps while the module was active.

Does that make sense...if so I should be in the proper range, correct?


Regarding the solar panel, I actually have one of these: First 235 Tips: VW Solar Panel for Battery Upkeep

My brother gave it to me when I bought his old TDI Jetta off him, it came with the car when he bought it new. I guess I will have to dig it out and see if it still works. The guy reporting in the link I posted claims it is good for 170mA max so that might actually take care of it. If my truck sits for a week or more, I will usually put the charger on it and I am amazed how much charge it will take before the charger shuts off. I wonder how much of that is the week or two's parasitic draw and how much is the design of the charging system just never really topping off the batteries even when the truck is being used. These darn trucks are so dependent on lots of available juice I'm really starting to focus on making sure I've done everything I can to help.
 
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