Alternator or Regulator?

[gijoecam]

The truck in question: '93 Ranger 4x4, 4.0 supercab, stx, bone stock (except for the Monroe Sensa-Tracs) 149,000 miles on it

Wierd thing happened today... I got in the Ranger, started it, and all was well... dropped it in gear and it stalled.... wierd?! Re-started, no problem, so I didn't think much of it. Then I notice that the battery light is on and the volt meter is showing about 10.5-11 volts. So I let it idle for a minute or two, and drive it around the parking lot a bit to see if it'll heal itsels fas it warms up... no beans. Let it idle for a bit longer to warm up, and revved it a few times... above 4k, it seems to charge just fine... gauge comes up, light goes out, but when it slows down, it dropps out again... One time, it stayed up at idle, but when I put it in drive, it dropped out again. I've noticed that for a couple of months, at idle everything is fine, but with the blower motor on high and/or the lights on, the volt gauge would swing down around 12 volts. (Seems like it's just a bit too much current draw for it)

I checked the belt tension (it's OK) and the obvious connections (all clean and tight). Is the alternator finally shot? Could I get away with just the regulator? I need help and fast... Parts stores are open tomorrow, but only for 1/2 day... I plan to pull it off first thing in the morning and have it tested, but their machine won't tell if it's the regulator, only if it's charging or not... It could test OK, and still not charge, right? I hate electrical problems....

-Joe-

 

[yob_yeknom]

Dead Link Removed

Looks like we're having the exact same problem. Let me know what you do and how it turns out because I guess I need to do the same to mine.

Thanks.

 

[Jason_25]

I may have what you guys are speaking of. Sometimes when I come to a stop, my RPM's will dip to around 300-400 and the truck will nearly stall and the battery light will come on and my headlights will dim if they're on.

 

[Stompah]

I had the same problem too. My initial thought was to change out the regulator. But all Exploder Alt's are internally regulated and around these parts of California, prices arent too affordable. So I changed out the whole alternator and fixed the problem.

Most charging systems go bad when the diodes wear out. Not too much would the stator or brushes go bad but when the diodes are under load (i.e. heater, A/C, Stereo Systems, etc.) that's when the alternator starts to fail. Don't mess with the regulator. All it does is adjust the voltages thus increasing the load on them diodes.

Just my two Abe's...

 

[Bill Kemp]

They can and perhaps have to check the alt. on the veh.
Dont take it off first. Go to the store and they'll check it.

 

[gijoecam]

I can't take it in to them running on just the battery reserve... I don't trust it to make it that far.

I agree it's probably the regulator or the diodes (which are a part of the regulator... they rectify the AC generated by the alternator) and the regulator can be replaced... their "internal" regulator is held on to the back of the housing with two screws. The fact that it charges when I rev it leads me away from the brushes/armature... It's got 149k on it, and I think it's the original (or replaced with OE) so it's due... I think I'm gonna replace the whole thing... Lifetime warranty alternator is $120... I'd like to upgrade to a higher output, but I can't get one in short order. Just the regulator is $55, but there's no guarantees that the brushes aren't on their last legs.... I'm still not sure which way I'm gonna go....

Yob Yeknom... I saw your post.... I take it you never got it fixed either?

-Joe-

 

[yob_yeknom]

Originally posted by gijoecam
Yob Yeknom... I saw your post.... I take it you never got it fixed either?

Not yet. I'm looking into a higher amp alternator also. That way I'll already have one for my future stereo system.

Have you been able to find any high output alternators?

 

[gijoecam]

Originally posted by yob_yeknom
Not yet. I'm looking into a higher amp alternator also. That way I'll already have one for my future stereo system.

Have you been able to find any high output alternators?

The only ones I found were from www.mralternator.com

They did a bulk buy on the ranger forums a few months back... they make a 170 and 200 amp, but I didn't want to wait. I replaced it with another one by Master Quality for $120 with a lifetime warranty. (They're a decent brand... I used to sell them when I worked there... VERY few problems with them... good remanufacturer... all new internal parts)

They tested the old one... when their tester loaded the alternator, I could actually see the brushes arcing to the armature through the back of the case... I could've rebuilt it, but didn't want the hassle, and needed it done today. It's back to normal, I guess. The volt gauge still drops a bit when I hit the lights and turn the blower on high, but it maintains 12 volts, so that's OK in my book.

-Joe-