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Alternator interchangabilty ?

M123KT-450

M123KT-450

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My Alternator seems to have about had it. . .I took a trip yesterday about 200miles round trip loaded with a car trailer and 3 ATVs my alter nator would run 14 volts for a few miles then drop back to 12.5 and sit there for about 50 miles then jump back up to 14.2 for 2 or 3 miles the then drop back off to 12.6. . .

My buddy is like well you have duel batteries and if there fully charged it might not kick in till it sences a draw some place. . .

I have never seen an Alternator do such a thing. . .any truth to that ?
I have seen Generators react this way but never an alt. . .

So is this thing Have to be a 6.5 Alt ?
or
Will other GM alts interchange with this unit ?

Mikey
 
My knowledge is limited to 6.5TD, 94-95 (not sure of 93) is the same alt.
96+ uses a different alt.

This is signifies by the placement of alt. 94-95 is on the driver side with AC compressor on the pass side. 96+ is on the passenger side with AC compressor on the driver side.

That does not mean it does not interchange, I am sure you can interchange it if the mounting bolt can be reversed.
 
My 96 was doing the same thing I bought a digital voltmeter that plugs into the lighter it reads pretty steady compared to the stock guage. I dip into the 13s sometimes but never into the 10s my guage reads.
 
yea my head lights stayed bright we were thinking it might be a funky guage ?

Mikey
 
Will a Gasser alt swap into this truck or dose it have to be a Diesel ?

Mikey
 
Check the body grounds at the battery to fender. A gasser alt. will work but you have to have the diesel pulley.
 
Pulley swaping ain't so bad. . .I'll give them grounds a good looking over in the AM. . . thanks that bit of info. . .:thumbsup:

Mikey
 
Not really. . .I would cycle my glowplugs n fire the beast up and the voltage wouldn't really fully recover. . .it sat at 12ish the whole ride home if i used the turn sigs then it jump to 14 for a just a few miles then slowly fade right back to 12. . .

Mikey
 
If you go with a different amperage alt than the one you have already you may need to change serpentine belts. IIRC there are about 4 different amp alts that were offered and 2 different case sizes.
 
My guage is funky too. I'm almost positive it is the grounds. I put a volt meter on the alt when the guage was reading low and it was at 15. My guess is faulty guage or grounds.
 
I'll go give it a looking over right now. . .

Ok the secondary battery is grounded right the Alt, the Radiator support grounds look nice clean and intacted, I guess i could run a new ground wire from bat to body but i am thinking this is all wishful thinking i am sure the Alt is shot. . .

Mike
 
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Check it at the batteries with a volt meter when it is reading low on the gauge. If it's like mine, the gauge can show 12-13 volts when there is actually over 14 at the battery. The gauges in these trucks suck. Mine usually reads low but for some reason the last few days shes readin' right on 14.

knock on wood.
 
Yea I am getting the feeling that anything having to do with a 6.5T powered truck sucks, they lack power they continually need attenchion . It is what it is just all part of being a 6.5 owner...

If ya aint fixing it your not driving it.

Anywho ill test it but I am sure its the alt !

Mikey
 
M123KT-450 said:
Yea I am getting the feeling that anything having to do with a 6.5T powered truck sucks, they lack power they continually need attenchion . It is what it is just all part of being a 6.5 owner...

If ya aint fixing it your not driving it.

Anywho ill test it but I am sure its the alt !

Mikey
Click to expand...

You say so... I've hardly touched my truck (other than regular maintainance) for 100K and I pull a 9800 lb 30' 5er in real mountains... I've got lots of power, get good fuel mileage, truck is highly reliable, and fixing the battery connections and grounds 3 years ago solved the low voltage issue.

I gotta believe the problem with your truck isn't the problem, Mikey... there's not much wrong with these trucks that can't be fixed.
 
Do yourself and us a favor sell that truck, we are quite over hearing how much you dislike it, we get the point you think you bought a lemon, sell it if it makes you so unhappy, or stop saying with every other thread you happen to post in how much it displeases you.

State your problem and we can help resolve it, if you choose to take our advice, but the incessant posting of your dislike of the truck has run it's course.

Often and this may not be the case here; it is the current or former owner that has turned the truck into a basket case, yours does not sound like a basket case, it does sound like a high mile older truck that was not cared for well in the past, and you will have to invest the time to correct the discrepancies, this would be the same for any other truck you might have purchased and it was not cared for.
 
Yea that fantastic sir I am glad your truck has been a top notch unit !

My 1 owner well maintained truck has been problematic...

Sure it can be fixed and it will be fixed cause as you can tell by my relics I run a truck till its dead !

I'm just going to keep smiling and keep right on fixing this truck !

Now as for the power or lack there this 50/50 blend of ATF n HP injector oil has greatly improved the power but its still just a bit sluggish...

Nothing I can't solve in due time weathers warming jobs are starting to come in so things will be addressed and corected !


Mikey
 
Attaboy, Mikey! Stick with it!

Look in the FAQ for a 'How-To' on fixing the battery connections... that's the first thing you need to do to fix up your charging issue... good alternator or not, these connections suck and can cause all kinds of mystery issues.
 
If you all will notice i haven't really done much pissing and moan or griping about this truck in a while i was just taking it as it came. . .I was just in the right mood to make a few pissy type comments about tonight but i didn't beat it to death i PMSed and moved along in the repair process. . .

yea its 95 yea its got 130k miles on it that to me don't mean much to me or IMO its a rather young truck and not so high milaged as most might think. . .I have trucks that are twice its age with triple the miles and they are still going down the road, Running strong Running healthy being trust worthy and even do it safely. . .

I'm am sorry if i get pissed and you all have to hear about. . .your the ones that are getting me threw the break downs as well I know that ! yea i do get hot and pissed off wouldn't you if the role was reversed ?. . .
But i do fix it and fix it again if need be because i don't replace truck when the body style changes i replace it when its dead !
I fix'em till there is nothing left to be fixed. . .

Mike
 
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