I have an Expedition with 115K miles and still has the original alternator. I would like to know when should I need to replace the alternator, I do alot of long distance travel and do not want to get breakdown in the middle of nowhere. Thanks.

 

Mine went out at about 90,000 or so. I replaced it with a Napa life time warrenteed unit so I won't have to pay for it again.
I have heard of people getting less and others much more. If it ain't broke, leave it alone.

 

It just all depends on how lucky you are. Most of them seem to last around 5 years or so, some shorter, some longer. Like WLF, I bought a lifetime warranty alternator from Autozone, so I don't have to pay for another one. I paid maybe $80 (don't remember) and put it on myself.

 

My alternator has almost 250,000 miles on it. The bearings were noisey and replaced at 165,000 miles, but everything else is original including the brushes. In fact, my truck still has the original battery.

 

Mine went out at 102K. One moment it's fine, the next the idiot light is on. Oh yeah, that volt "gauge" that we have........... Not worth a damn!! Stupid needle points at the same general location with the dead alt as it does with the new one!

If it was not for the actual light, I would have never known the alt was not charging..... (until the motor would have died anyway!)

The alt in my wifes Plymouth is over 13 years old and is original with 125k on it.

I've had brand new alts that went out on me too. Sure, it was replaced for free, but I still had the inconveinence of having to change it again!

Hook up an actual multimeter that reads DC Volts and see what the output is when idling. If it's in the 14v range, then the alt is fine. If you want peace of mind, change it. Only costs around $100 for a 130 amp alt. Keep the old one as a spare??

 

on our 97 lariat, with 177,000 mi. we have teh original alternator w/ original brushes/bearings etc.

 

Depends on a few things.

These will shorten the life of both the alternator and the battery generally...
-Short trips, lots of starts
-Huge stereo system
-Lots of electrical accessories
-Extreme hot or cold
-Luck

I'm sure there are a few other items that will shorten the average life but I have seen them go as quickly as 40k and some that have over a 100k and still no problem. A battery normally last about 3-5 years but will have a much shorter life if not used much or you drain it a lot like a stereo system of off road lights when the engine is not on.

I agree with the above mentioned that the voltage guage on the Fords are practically useless, if it shows that it is off then you may really have a problem.

 

I cant believe Bent6's battery life. my truck is 13 yrs old 100,000+, I am on my 3rd battery, same alternator, checked with my auto parts supplier and he checked my alt. said it was fine. he mentioned ford had a prob. with the wires coming to the alt., said they were heating up and melting with certain year models. I was ready to lay out 100.00 for a new one but I might be able to buy me some suds now. LOL

 

Here's a bad story. The alternator and the battery both died while my wife was going to the mall and I was at work (~60k miles). They claim 1 took out the other. She pulled into Sears when the whole thing shut down. 1 rebuilt alternator and 1 Sears Die Hard @ $500! Ouch! and I was helpless to do anything!

 

BENT6 or anyone on the forum, I recently purchased a 1999 supercab with 23800+ miles on it and the alternator is noisey ,I guess its the berings, can I repalce them or must it be rebuilt . Can anyone advise me which and how to replace berings if can be done. Thanks folks .

This site is GREAT!!!! a wealth of info and GREAT people !!!!

phoneman

 

MitchF150:

I hear you about some of the gauges in the trucks. They just point in one area not really telling you if things are normal or not until to LATE...

You would think Ford would just save some money like on the voltage gauge and just "paint" a line thus no need for a needle to move from 0 when not running to its normal resting spot when running...

 

My '97 now has 160,000 miles on it. Original alternator and original battery in it still. Truck was new in 10/96 - so things are about 6 1/2 years old now. No problems. Still starts right up in -25 F weather!

My '99 has 84,000 on it now, and everything is also factory equipment on that one too with no issues.

 

Sorry for the little off topic, but some of our guages are just simple on-off type of things light idiot lights, not true guages. Like the Oil pressure. anyone with an aftermarket one will tell you that pressure is high when you first start up a cold engine, close to 80PSI, then drops to a typical 25-40psi. But our guages needle never moves. I have a feeling the voltage one is similar.

 

01,

yeah, don't get me started on these "gauges" they put in these trucks. What a total waste of space.

Heck, the gas gauge is not even that accurate! I can go 200 miles on the first 1/2 tank when it's full. Then only about 75 - 100 miles on the last 1/2 before the low fuel light comes on........

That's why when I'm on a road trip, I start looking for gas at the 1/2 tank mark! Especially when I'm towing my trailer!

 

same here my gas guage doesnt move off of 100% full until about 65 miles.