Alternator - Help?

[commradd]

I have a 1991 2wd ext cab Ranger. The alternator went out about a week ago. I put a new alternator in last weekend and last night the new one appears to have gone out. So here's a bit more detail: When the first alternator went out (a sticker on it said remanufactured) I first noticed the battery light on the dash came on, then I noticed the battery gauge was really low. There was also a really odd smell coming from under the hood and I couldn't pinpoint because of the fan, but I guess it wouldn't surprise me if it was the alternator burning up. The pickup has about 150,000 miles by the way, and i've only owned it for about 8,000 miles. I took the alternator in to have it tested and they said it was bad. So i spent $75 on a new one with a lifetime warranty and installed it. Everything worked fine after that till last night, then, same song second verse. Except I didn't smell anything this time. Battery light is on, gauge is low, and my headlights were getting dim driving home last night. Any idea what would cause 2 alternators to go out like this, other than random chance? I appreciate any help on this.

 

[kimcrwbr1]

When you change anything in the charging circuit you need to make sure everything is good is your battery in good condition and was it charged fully when you put the new alternator in. There is a good possibility you got a lemon alternator but did you check the system after you installed it. you can possibly warranty that alternator if not your SOL but when you install the new one before you start it take all your grounds apart and sand them metal to metal every one you can find and make sure they are tite. Kinna sounds like the battery to me so charge it first it should read 12.5 volts fully charged or take it and have it checked just go to a different store just in case for the warranty on the alternator anyway with a good battery terminals and grounds start it up and check the volts at about 1500 rpm it should be upwards 14.8-15 v and your guage should be in the middle unless it reads volts if you dont have a volt meter take it to the part store for a diagnostic but dont just run it till you know it is all good. It is not nice to make a new alternator charge a fully discharged battery your asking for trouble they tend to say FO

 

[AllanD]

Does your truck use a slip connector for the main power plug to the alternator or is there a stud with a nut?

If you have the big slip connector the problem is probably the connector itself.

you can EASILY upgrade to the later style alternator (it's literally a bolt on swap)
by replacing the alternator charging harness... trace the wires from the alternator
there's a small white plug where the field connections plug into the main harness
(near the rear edge of the battery tray) and two big ring terminals on the batery side of the starter relay.

You'll need that mini-harness off of any 1993-94 Explorer along with the later style alternator.

As a Note the alternator you have now is likely either a 75Amp or an 85Amp.

If you upgrade to the later style it'll be either a 95Amp or a 130Amp.

AD

 

[kimcrwbr1]

Hopefully you didnt have a wire fire be sure to check for direct shorts burnt/cracked wires melted connections give it a good eyeball and yea look at the altermator connector good make sure the wires are pushed all the way in not burnt or corroded.

 

[kimcrwbr1]

When your connecting the battery pos first the take the neg and touch the terminal you should get a tiny spark that will be the computer and radio memory if it arks you have a short and dont hook it up till you find the problem