I've got a 97 F150 4.6L. While it was running, I tested the voltage at the battery and it was 12.1. So I took the truck down to Advance Auto and they confirmed the alternator was bad. I bought a new one and a belt to go with it. I looked through several threads, but still have a couple of questions.

Some people found that the light was on because of a bad fuse. My owner manual shows no fuse for the alternator. Do I have one?

How tough a job is this? It looks like if I take the splash pan off underneath, it will be the best possible way to unload the tensioner with a 1/2 breaker bar. I have another person who can help with the new belt. Would this be the best way?

Finally, is it really necessary to steel wool all the pullies and clean off with brake clean?

I'm going to do the job tomorrow, so any help today would be greatly appreciated!

 

My 1999 F150 5.4L engine has the Alternator Field fuse listed as number 11 in the power distribution box. I also cannot find a junction box for the mega fuse and I am wondering if they just route it through the fusable link from the battery. I did some more checking and my Haynes manual has a diagram that does not match the wiring in my truck. My alternator has a direct BLK/ORG wire to the starter motor relay I am guessing that both the Alternator and the Starter run though the fuseable link to the battery.

 

Thanks temp. I'll check the fuse first. How did you loosen the tension on the belt? Up top or from the bottom?

 

There are some little catches on each half of my fuseable link.

I would think that if the fuseable link was gone then the truck would not start but I have not traced the wiring with an ohm meter. You do have my interest perked though. All I would have to do is disconnect some wiring from the starter motor relay and and trace where some of them go. Im mainly interested in the fuseable link path at this point.

 

I did verify that the fuseable link from the battery goes to the starter relay. The fuseable link connection is highlighted in RED. The YELLOW circle shows where the fuseable link; alternator and another large red cable which I assume goes to the power distribution box but I have not traced that connection. I do know that if I disconnect that other red cable then the light in my engine compartment goes out so again I assume it supplies power to the power distribution box.