Have a 99 f150 with bad alternator.
Local parts stores have either 95 or 130 amp altenator listed. Not sure which one is on it now. Below is a partial picture of the label on the old one. I have the missing part of the label in picture.
As you can see it says 12v 95 A at the top, but underneath it says or said @6000 rpm it produces 122 amps. The top label makes me think it’s 95 amp, but the other part makes me think 130.
If anyone deals with alternators a lot...., please explain and do I need 95 or 130 amp alt.
1999 f150 xlt, had ac, no power seats and no towing package.
Thanks
I would agree with Jose'.....the 95 amp version should be fine unless you have additional equipment that would require the extra output of the larger 120 amp option. I formerly had a 1999 F-150 & it was equipped with the 95 amp alternator. When the original unit needed replaced I purchased a new one with the same output rating. My son is still driving this truck & the charging system has always been adequate. Here's an interesting story about when the original alternator quit working. I was about 35 miles from home & noticed that my headlights were starting to dim. The volt meter verified my suspicion.....the alternator had quit producing amperage & the truck was relying strictly on the available battery voltage to keep running. I connected my jumper pack & was still able to barely close the hood. We had just enough juice to make it home. When we were a mile or so from town I turned off the headlights, turned on my 4 way flashers, & managed to make it back to our shop. The motor was starting to stumble as we drove through town.....undoubtedly due to the ECM not getting enough voltage. Mike
Thanks for the replies guys.
I charged my battery and tried to make the 30 mile drive in the daylight yesterday. Lol she died a mile from home. Recharged the battery and it’s home and in the garage now. Gonna put an alternator on it today.
Thanks for the replies guys.
I charged my battery and tried to make the 30 mile drive in the daylight yesterday. Lol she died a mile from home. Recharged the battery and it’s home and in the garage now. Gonna put an alternator on it today.
I'm suspecting the rating is for alternator shaft RPM and not engine RPM.
Most damper pullies that run the belt are larger diameter than the alternator pulley, thus creating a higher alternator shaft speed.
95 will do the job for you I had a full size conversion van with front & rear air all kinds of pretty lights in the ceiling and full power everywhere else now it took a 130amp so 95 will do it for you
New alternator, ended up with 130 amp, same price and in stock at advanced. Still no charge going to the battery, belt seems tight enough, all the wires plugged in, “alternator field” fuse in fuse box isn’t blown. Truck runs and slowly drains the battery.(used a little volt meter, same voltage with truck off or running) the battery is new and tests good
one of the large gauge + wires coming off the battery is marked “fusible link” . From what I’ve read, that wire probably goes to alternator.
Sitting in a tree right now, going inspect the fusible link later today.
btw my alternator problems started just after replacing the starter(turned out to be a bad + wire to starter. Odd coincidence
Sounds like you have a bad connection. Check all your wires, including your grounds. Not sure how your alt gets it + power but it maybe the positive connection at the starter.
Uhhhhh......my alternator gets its power from the starter relay on firewall...... the relay I replaced in the dark at speedway when my starter was out...... lol.... need I say any more.....it’s charging now! Thanks guys.
Glad you got it figured out. I went through a similar issue with my 97 Dodge a few years ago. I was about 10 miles from Home and the lights started to get dim and my battery gauge on the dash was doing all kinds of goofy crap then the generator light came on in the dash. It was starting to get dark when all the electricity in the truck shut off but luckily the mechanical diesel still ran just fine and got me home.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Ohio Game Fishing
3M posts
62.2K members
Since 2004
A forum community dedicated to Ohio’s fishers and enthusiasts. Come join the discussion about safety, gear, tackle, tips, tricks, reviews, reports, accessories, classifieds, and more!