We have a 2006 Ford E350 6.8L van that has a constant battery drain of about 1.1 amps with the ignition switched off. I used a good Amp meter and took the following measurements in the engine compartment fuse box. Fuse 8 going to the I/P Fuses 5, 11, 23, 38, 4, 10, 16, 22, 28, 32 the draw is 710 mA. Aftermarket security system 460 mA. Fuse 23 Ignition switch, Fuse Panel 20 mA. I also noted a draw on fuse 6 Left trailer turn signal 650 mA and fuse 12 engine compartment fuses 25, 27 650 mA. But these last two draws disappeared after we replaced the fuse link between the battery and the engine compartment fuse box. We have also checked the grounding straps on the engine and chassis and they look good. The battery is new. Any ideas on next steps I should take to diagnosis this problem. I checked the interior fuses and none of them are drawing any amperage. Please advise.
WAY too high! The total draw should be well below 100 mA.
So from your post, after replacing the fuse link, the alarm and the engine compartment fuses draw dropped to zero? Or what?
Start by pulling the IP fuses 5, 11, 23 ect one by one until you find the item drawing that much current. Be sure the door switch is off so that the truck will go to “sleep” with all the electronics at their lowest draw level.
If any of those lead to an aftermarket radio, pull that one first. You saw how much the aftermarket alarm draws. I’d re-check the alarm again. If, for some reason the alarm wasn’t “asleep” and the fuse link fixed it, you’ll want to make sure it isn’t drawing 100 mA or more while “asleep”
Are you waiting long enough, after shutting off the vehicle . . . ?!
Some modules need a LONG time to go to sleep
Hook up your meter
Come back after 30 minutes
What is the reading?
And when you say you’re using a good meter, I assume Fluke or comparable quality . . . ?!
And just how are you measuring current draw?
In-line . . . ?!
Amp clamp . . . ?!
I don’t know about anybody else, but I’ve found in-line to be more accurate
Wouldn’t an amp clamp only work on alternating current?
You can also use them to measure dc . . . assuming your meter’s capable of doing that
We waited at least four hours after the vehicle was shut off. Yes, I’m using my Fluke meter. I measure current in line, that meter doesn’t have a clamp.
There are specially made amp clamps used to measure DC current. They use a Hall Effect sensor to sense the current. I have never used an AC clamp-on to measure DC current. If it does pick up a reading I assume it would not read the current correctly.
When you turn the vehicle off and wait for things to go into the sleep mode you can’t break the circuit and install your meter. When you reconnect the power through the meter that circuit will now not be in the sleep mode. You would have to wait for that circuit to go back to sleep again. Most circuits only require a few minutes to go to sleep but some can take about 20 to 30 minutes to do that from what I understand.
Most normal current draws on vehicles are under 50 milliamps, and most are around 20 ma. from what I have seen in the past. The security system current draw seems out of spec to me so there may be an issue with it.
Thanks. I checked them out last night on the Fluke website. Pricey!
I do wonder about the reason for the fusible link replacement. Inadvertently popped during testing or just gave up on its own? That brings up the possibility of a shorted harness somewhere.
I do know that my current Lincoln, past Lincoln, and the Lincoln Aviator my son owned all had a current draw of a bit over 700 Milliamperes before things went to sleep. Just wondering if for whatever reason (harness short, who knows) that things are not going to sleep since the current draw is all very similar.
It it were me I would spend some money on the Helm publication with the current flow diagrams. It makes wire tracing and so on much easier by showing connector locations and so on.
About 90 bucks from Helm although cheaper used ones can be found on eBay and so on. To me it’s worth 90 bucks if needed…