here's a tip ........
have had several 07 to 09 rangers 4.0 no charge conditition fuse link feed wire rubbed in two by plastic inner fender under battery box
that may be your problem. it cuts the voltage down an dalternator won't charge. there are three so check all three two should be on relay pic included.

So I have located two links (labelled as links) red power from battery to fuse panel to link and turns into blue w/green stripe. I probed either side with buzzer and got power both sides of it. also probed red wire (smaller) bothsides of link red to wire/brown. cant locate the other link. is probing for power on either side good enough?

theother linkis under the battery box rubs oninner fender well re read the tip and yes a test light or volt meter is better

are you referring to battery box as fuse panel area or actually under battery

under the battery box like it says.

in this case no wires run under any box cant not see anything damaged.anywhere. found third link and measured power on either end of all three. All good.! When the vehicle first came it wasnt charging. My assistant tooki it out and charged it. I installed the next day and battery was taking a charge fine, ran for 2-3 days and now no charge. Thats when i installed new alt.

I have power to alt and power to the red wire located in the three wire plug on alt. Should there not be power to another wire while its running. Like an output of power. Sorry not the greatest at this stuff

have a pro look at thisyou should have battery voltage at both red sconnections at alternator. you aren't understanding at all. the battery HAS to be reomved andprobably battery box and the link has to be looked at for being rubbed off.

2007 ford ranger no charge w/new alternator w/power on both red wires-full batt. voltage. Note batt. light on dash does not light anytime.???

Could you explain to me exactly what is the fusable link and where I would find it? I think that I have found them but I want to be sure. I did find a wire that had a sticker on it that said fuse links. Does it have an actual fuse in it?

Check the fuseable link between alt and battery.

it is a wire that is smaller than the load wire. when there is too much draw from a short, the wire burns out instead of frying the harness

roy

where would that be located? and would i just probe for power on either side?

Battery light came on. Took to shop, they said alternator was bad and replaced. After replacing they said still not charging, was in circuit and put old alternator back on and refunded money.

Took to Ford dealer repair shop. They checked connection and ground and said it is definitely the alternator. they said new one other shop installed was bad to begin with. Ford dealer installed new one and still not charging. they say their new one was also bad. They are in process of putting on 3rd new alternator now. If this does not work, I would appreciate any suggestions.

Sound's like a wiring issue not just one bad alternator after another being put on.Let me know if the new alternator won't work and we will go from there.

they have put the new alternator on and now say it is not the alternator, they are thinking the fused relay??

I posted a wire diagram of your alternator it look's like all they had to do at the first place you took it was check for power to the two wire's that go to the alternator that have fuse link's to them.Pretty simple especially with seeing the new alternator didn't fix the problem.Sound's like no one that has looked at the truck want's to or knows how to check the wiring to the alternator.That's where i would start checking the wiring to the alternator.

I have replaced the battery, alternator, and starter, the truck will crank but the battery won't stay charged. One mechanic said it was a fuse under the hood. we have checked all the fuses in the power distribution box and none of them are bad. So where do we go from here?

Did you check for valtage anywhere? Did you check for voltage at the applicable fuses? Use a voltage tester. The fuse circuits in the diagram go hot with the key on. The fusible links are hot all the time, should be voltage on both sides of link.

If the battery is down take it off and get it charged, otherwise, we can do any testing.