Normal Amp Draw

[kreezy84]

Hi guys and gals, trying to aquire some information about my 2008 Ford Focus. All the videos I've watched have said that a 50 miliamp draw is the norm for car batteries, but I have also read that some guys get a 1.2-1.4 amp draw out of their Focus. Mine is reading about 1.4, is this the norm or do I need to start trouble shooting a parasitic draw? Thank for your help.

[Sponsor]

[mikeeshaq]

I think that it takes a while for the electronics to 'go to sleep' then there will be much less current flow
15 minutes to 30 minutes?

[kreezy84]

I checked it 3 hours later and got a reading of 1.43 amps, but after holding the leads on there for about 30 seconds the amps dropped down to 200 miliamps, is that a reasonable current draw for these cars? I just purchased this car used and all the electronics, memory, and computer stuff is new to me.

[mikeeshaq]

My memory is fuzzy

I think if you happened to open a door to open up the engine hood then some of the electronics may come back to 'life'. Since there is no electrical switch on the hood then leave it open to do testing.

Are you using a DC clamp on ammeter? then that is the best way, then you avoid anything that might trigger the electronics to 'wake up'

But I think 200 ma is close to reasonable

There is more computing power in these present day cars than what went to the moon!

[kreezy84]

Well, I left the negative cable disconnected during that 3 hour duration. Would opening the door still have that affect?

[a_2000_se]

Originally Posted by kreezy84

Well, I left the negative cable disconnected during that 3 hour duration. Would opening the door still have that affect?

It's not that you had the negative cable disconnected for 3 hours but rather that you 'reconnected the negative cable' when you attempted to measure the current draw when you "held" the leads in series with the negative cable.

As mikeeshaq mentioned a clamp meter would be best to avoiding the possibility of 'waking' something up. You are resetting something (recharging capacitors) every time you break and then make the power connection - with the meter in series. (Radio?, PCM or at least part of the PCM - PAS.....)

[kreezy84]

Thanks for the help.

[mikeeshaq]

A DC clamp on ammeter is not a cheap thing to buy [nor easy to find, it has a 'Hall Effect' sensor]
Found one on Ebay from China for less that $100

For certain a_2000_se is correct. Placing an ammeter on the open ground lead will wake up stuff

My memory is hazy


I think

The electronics will go to 'sleep' in stages

[a_2000_se]

Just got the most recent flyer advertisement in the mail from Harbor Freight.

You can now get Clamp-On meters cheaply. CEN-TECH #96308 and #95683, $11.99 and $13.99 respectively. Haven't seen the spec's on them yet but maybe one of the two will be good for automotive applications.

[mikeeshaq]

Harbor Freight do have cheap clamp-on ammeters except they are AC not DC