Ford Ranger Altenator
Asked by captain Jun 12, 2020 at 07:07 AM about the 2011 Ford Ranger XL
Question type: Maintenance & Repair
I have a Ford Ranger with a 4 Cylinder and a Automatic. It's not Keeping the
battery up so I bought a new Battery however that didn't help. So I then just
bought a New Altenator and installed it Day before Yesterday and drove it
about 20 Miles and it The Brand New Altenator quit already. What would
cause this? The Wiring Harness checks out good, all Fuses are good,
everything else checks out good as well. I also have a 2006 Ford Escape
that is doing the same thing. As with the Ranger The Escape's Wiring
Harness Checks out ok as does the Fuses and everything else. Spmething
is killing the Altenators. What could it be?
9 Answers
Do you have a parasitic drain? Also you need to do a ground check on the positive and negative side of system. Voltmeter is all you need.
Parasitic drain - when a circuit in car drains battery while car is off. Modules don’t go to sleep or you have a short in a circuit and it slowly drains battery. 50 miliamps is max drain allowed during key off after modules go to sleep. My experiences with customers has been when a car has a parasitic drain and the battery is low, when you do get car jumped or it starts, the alternator has to work too hard bringing that battery up to spec that it ruins alternator.
Also some Fords only work with a Motorcraft alternator due to it being ECU controlled. Have had many in my shop like that. Recently a Ford five hundred
Was it a New alternator or a remanufactured one? Reman's sometimes are bad right out of the box. Have it tested before you start going through the wiring.
I never buy remanufactured alternators, starters or master cylinders. I also use Denso starters and alternators when possible. They are expensive but they last. Outside of my customers, I have only replaced 1 Denso alternator in 34 years in my personal vehicles. Never yes never had a Denso starter go out. Most of my cars have 250K and are 15-20 years old.
