How many amps should my 1992 F150 draw when it's not running and with no accessories (like the interior lamp)? At the battery I'm pulling .17 amps and I checked my dad's 2008 F150 and it pulls .18 A. Bigger question here being....my battery will die after about 3 days without running. I figured I would check the draw at the battery to see if I have something draining the battery when it's not on. If my amperage draw sounds right, what else should I check? With the truck running my battery is getting 14.4V from the alternator, does that sound right?

I'm kind of looking for brainstorming here on possible things to check. With the truck off I've pulled every fuse and stuck my voltmeter on them and nothing is pulling power except for the interior lights.

 

WOW, if either of those vehicles are pulling 0.17 to 0.18amps thats way too much, shouldn't be more than 50mA or 0.05amps. But thats with the under hood light off, interior etc.

how did you do your draw test? unhook the battery negative cable and set the multimeter in series with the negative terminal and the cable. If you have a mA setting use that. Id also do a leak test across your battery, so test the amp leak of the battery across its terminals unhooked from the vehicle.

Shouldn't be more than a few mA, if more while doing the leak test the plates in the battery are bad.

 

I did the draw with both battery cables attached. I will redo as you stated when I get a chance.

 

Yeah, sounds like you had hood lights on or something else. Sylver is spot on.

 

the hood light is easy to turn off, they have a float switch inside them, just have to flick it and it turns off mine does and others Ive seen do too.

 

I don't have a hood light. This truck could not be any more basic than it is.

 

When your truck is cold or has sat for about an hour, do the draw test. If you are still getting a high amp reading, there is something else going on like a short in a wire harness or something is still running in the background. Have you pulled any codes? Do you have an after market radio or fog lights?

 

I don't have any check engine lights so I haven't tried to pull a code, if that's what you mean. No after market anything except I've changed one 6.5" door speaker. I soldered those leads and wrapped each wire in electrical tape so I don't think it's that.

 

Well try the test for draw and leak like i explained and see if thats gets you anywhere. If not well go from there to try and fix it.

 

Negative battery cable off, multi-meter then connecting the negative cable to the negative terminal on the battery gives me .17 mA. Stupid comment/question. I get .17 when I put the positive (red) multi-meter cable on the battery cable. If I put the black multi-meter cable on the negative battery cable then I get .02 mA. Does that make sense? Anyway, the truck had been off for a couple hours and there were no accessories on.

Both battery cables off I get .02 mA across the terminals. For the record, this is a brand new battery because I was having this problem with a prior battery and I thought it was the battery so I got a new one from AutoZone.