06 exp

[Shaggyboom]

I have a 06 expedition..... so I have an issues car is running off the battery for some reason I've done the following

Checked battery for good charge
Check alternator on a alternator stand
Removed fuse from rear wiper

What happened was woke up wife's rig was dead swapped the battery it died again located bad rear wiper motor causing issue so I took the fuse out. Checked the alternator they said it was good. It died again so I took it up to auto zone put it on a test for the battery it showed it was running off the battery and not alternato .

What's next any ideas

 

[Hamfisted]

How many miles on the Expy ? Check the voltage at the outlet on the alternator with a multimeter with the engine running. It should be 13.5v-14.5v . Then check the positive post on the battery with the engine running, it should be about the same. If you're getting the correct voltage at the back of the alternator, but not at the battery, you may need to replace that cable. If you're not getting the voltage at the back of the alternator you probably just need a new Motorcraft alternator. Get a Motorcraft from Rock Auto, not the cheap crap they sell at AutoZone or Advance Auto.


https://www.rockauto.com/en/catalog...432128,electrical,alternator+/+generator,2412

 

[Shaggyboom]

112,000 mile . K sounds good I'll check both thank . Ya it's weird they did a test on the alt said it was good with it of .

 

[Hamfisted]

Yeah, those bench tests don't take into account the alternator talking to the vehicle's PCM and such.

 

[dogman]

check for corrosion on the cables and terminals. It doesnt take much to have too much resistance.