Hey guys,

I need your advice.
Friday afternoon while out running errands my '97 F-250, 5.4L, cranked over slowly. Was alarmimng since it has been fine all week. It started and home I went. Unfortunately I didn't think to look at the gages.
Sunday I went to move the truck while doing yard work and the battery was dead. I popped the cell caps and plenty of water there. Out came the charger and set it to a 10 amp charge while I did other things. After about fifteen minutes I set the charger to "Jump Start" and cranked it over. Volt meter reading normal, disconnected the charger and the gage went to bottom of scale. I moved the truck aside and left it running for about ten minutes. Came back to move it again and the instrument panel gages weren't working at all. Volt meter all the way down. As I moved the truck it began to run real rough, close to stalling. Parked it and put the charger back on.
As a test I turned the key on with the charger attached and the gages came to life. Battery took about 5 hours to charge. Must have been really dead.
Battery was replaced in July of laat year. I Know, it could still have a shorted cell.
Alternator has never been changed in 180,000 miles.

What do you think???

 

Likely yes the alternator is dead. To confirm measure battery voltage while engine is running, it should be above 13.3v, closer to 14.2v when engine first starts. 180K miles is good life.

 

Read this caption:

 

Well, aternator was dead.
Thanks Steve83, I had seen a similar diagram before. Output was zip.
Only took about 45 min to get it apart. Not bad. It'll take less getting together.

Walked out of PepBoys 233.00 lighter.
166.00 for the alt and another 52.00 for a new belt. I didn't get it together last night. After a 12 hour work day I was beat. Finish it tonight.

 

Another job well done.
Had a heck of a time getting the belt over the alternator pulley. Darn tensioner has a limited amount of travel. Ended up removing all but one mounting bolt letting the alt pivot down as far as possible. Then it slipped on. Used a prybar to move the alt back into place and bolted.
Battery voltage was 12.4V before starting and 14.8 running at idle.
Glad that's over with. I'm getting too old for this.

Thanks guys!

 

Sounds like they may have sold you the wrong belt. Shouldn't have to do that to get the belt on. I am assuming you tried with the proper tool on the tensioner and at full deflection it still wouldn't go on?

 

Yeah, it was the right length.
If a 1/2" breaker bar and a 16" length of pipe for added leverage is correct then I had the right tool. At full deflection the tensioner just doesn't pivot far enough.
I thought belt was short too. All I needed as another 1/2" and it would have slipped right on. This is only the second time I replaced it and still have the factory belt as a spare. Same length. I even crawled under the truck to make sure it was routed where it should be.
Once installed the tensioner is right in the middle of the operating range.
I kind or remember it being a pain the last time too, but didn't move any accessory to get it on. I just didn't feel like struggling this time.

 

Then they sold you the wrong belt. Try to read the numbers printed on the old belt. One of them should be a combination of a letter (usually K or G) followed by "6", and 4 more digits ending in 0 or 5. Maybe 1105K6 or G61105. That's the belt size in inches (110.5") and the number of ribs (6). Then compare it to the new belt. Do some online searching to find the correct belt for your engine/options.

 

I'll see if the original belt has any markings left.
I'll also compare the new belt number to the one it replaced.

I think I mis-stated how much more I had to go for it to slip on. I meant I needed more travel out of the tensioner not a longer belt. With the tensioner at full deflection the belt comes very close to slipping over the alt pulley. I could have used a screw driver to get it over the pulley lip but didn't want to.
As I mentioned I did physically compare the one I just bought to the original and it was the same length. That's why I also mentioned that after installation the tensioner was in the middle of it's operating range.
When I bought the first replacement belt I kept the sleeve it came in to store the original. I had it hidden away in a cabinet, totally forgetting I had it. When I found it I wasn't sure what it was for so I looked up the part number. I found it was for my truck and a direct replacement.

 

Somethings still not right. If you can't get the belt on, then either 1) it's not long enough, or 2) the tensioner isn't moving far enough, or 3) you're putting it on wrong, or 4) you're putting onto the wrong pulley last. Generally, the last pulley you put it onto should be one without a lip (a smooth pulley).

*************EDIT*************

 

I think Steve hit the nail on the head!

 

Belt not long enough?
I checked the original belt for numbers and managed to see them. Cross referenced that with the two replacment part numbers and according to each of the specifications they are the same length as the original.

The tensioner isn't moving far enough?
Yes, that was the problem. There is a stop point cast into the tensioner mounting bracket that prevents the arm from rotating past a specific angle. If that wasn't there we wouldn't be having this conversation.

You're putting it on wrong?
It's on correctly, followed the diagram on the radiator support exactly.
Even crawled under the engine to be sure the belt wasn't around a bolt or cought on a pulley edge.

You're putting onto the wrong pulley last?
OK, the only pulley without a lip is the water pump. There it would have slipped on.
Didn't think about that. Next time.


Thanks for all the input.
I made notes in the book and that'll help next time.
Truck is runnig fine. Better than with the old alternator actually.

 

If the tensioner moves to the stop, then it's moving far enough. Some of them aren't fully-enclosed & can collect debris in the coils of the spring, causing them to bind before reaching the stop.

Two other possibility that just occurred to me are 5) you have the wrong pullies (over/underdrive, or just incorrect replacements), or 6) a FEAD accessory has been swapped requiring a different belt, like this:



I realize those probably don't apply to you, but they should have been in my list above.