Does anyone know how to measure the amp drain coming off the battery with a standard multimeter? I have a 97 F150 XLT 4.6. When I turn the truck off and let all the lights go out the truck is still drawing approx. 4 amps from the battery. This was confirmed with a test on the battery/alternator at auto zone using their tester which test for that. I would love to test this myself at home and try to fix it.Any help would be appreciated.
I have a tool sold by SNAP ON that connects between the battery neg. and the removed neg. cable which will allow you to hook up an amp meter and turn a **** which allows the current to then pass thru the meter. Then you can pull fuses until the demon is found.
Here's a pic how to. One important thing is when you hook up the ampmeter. DO NOT turn on the ignition key (on). Most meters will only handle 10-20 amps. Turning the ignition may/will exceed that, and will blow your meter's fuse.
Easy way is just to unhook the positive battery terminal and hook the ampmeter in between the "+" post and power cable. A 4 amperage draw does seem alittle high, but in todays electronics it is possible. I will be installing a bigger battery this weekend, so I'll give it a try and give you a reply on what I get.
YOU MUST BE CAREFUL.
You can not connect a standard multimeter in series like the ampmeter unless your multimter is rated as an ampmeter. You will fry the unit (and maybe other things as well). Remember that measuring voltage is not the same as handling a current.
2000 F-150 XLT Sport, Silver 4-door Supercab StyleSide
Short Bed (Only way to fit in the garage)
17" Sport Wheels with BFG tires, 3.55 R, 4.6l V8, Auto (First one in 20 years)
In-Dash Single CD Player, 60/40 Split bench dark graphite
Mods So Far Fumoto Drain Valve, K&N Filter, Gatorback Spray-In Bedliner,
Llumar ProShield Window Tint, WMS Velocity Tube
If you want to test the draw with everything off, like it would be in normal use, you may need to sequence it.
Your DVM ammeter probably won't have enough range to handle ignition ON (fuel pump draw mainly), so will have to slip connections.
Pop off neg terminal cable.
Put cable back on, but don't tighten anything. This was all just to be able to get it off easy later.
Turn key to ON.
Wait for controller to time out the lights (underhood light is easy).
Put ammeter neg lead on neg center post of battery.
Pos lead of ammeter to neg cable. Ammeter will read zero, since its shorted, that's OK here.
Now, (more hands helps!), slip the neg cable off the battery post without breaking the ammeter connections.
Ammeter will now read your timed-out OFF draw.
Don't turn it back to ignition ON without putting neg cable back on battery post, or disconnecting ammeter, or you could blow your DVM's ammeter (or its internal fuse).
4 amp draw in sleep mode is too high. But be sure it went into sleep mode. Wait.
Be careful with this...it only takes less than 1 amp to kill you.
1999 F-150 Sport Supercab
Bright Red 4.6L Auto
Billet Grill, Billet Ant, Clear Corners, Sony CD Player, Pioneers in all doors, Kicker 100si Amp, MTX preformed underseat box. Fiberglass Bed Cover
2000 Expy Sport
Black, Grey Leather 5.4L
Clear Corners, Alpine CD Player, Punch 150 Amp, JL Audio preformed sub box in rear panel.
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