Alternator or connection ?

[dlmcgehee1]

I have never had an alternator get weak. My experiences have been that that all of a sudden fail, completely.
Could this be a connection somewhere? Or is the alternator going out?

 

[TXSunDevil]

I would put a multimeter on the battery while running. See what voltage you get there but 11V looks like a shot alternator to me.

 

[flintknapper]

Always check connections first (leads, grounds, etc), but IF that reading is accurate, your alternator is No Bueno..

 

[RobRed]

The 100 ALT tends to die with a heads up as you see. If not noticed then they appear to die "suddenly". 200k miles is well worn and shouldn't be a surprise. I changed mine at 188k. It was starting to be in the low 12v range so I put a big Amp replacement.

 

[dlmcgehee1]

Multi multimeter confirms scanguage reading.

Thanks guys.
Like I said, any problem I've ever had with an alt was a sudden death, never a slow one. This confused me.
I appreciate all the comments.

 

[dlmcgehee1]

The 100 ALT tends to die with a heads up as you see. If not noticed then they appear to die "suddenly". 200k miles is well worn and shouldn't be a surprise. I changed mine at 188k. It was starting to be in the low 12v range so I put a big Amp replacement.

How big? 120? 150?

 

[Rolocado]

How big? 120? 150?

I'm in the same boat and it appears to depend on what year you have. Later trucks use 120, I have a 2000 and it's a 100 amp. Someone correct me if I'm wrong

 

[jerryb]

270605036084 130amp for 2006

 

[dlmcgehee1]

I'm in the same boat and it appears to depend on what year you have. Later trucks use 120, I have a 2000 and it's a 100 amp. Someone correct me if I'm wrong

I went with the Napa reman 100 amp. It's all I could find in stock, and I need to get this truck back on the road.

 

[RobRed]

I went DC Power Systems 180 AMP - the beauty of this ALT is it puts out 90 amps at idle so battery charging is quick!

 

[nissanh]

You should have replaced the brush kit.

 

[dlmcgehee1]

Got this sucker in there.
Wasn't too bad of a job working from the bottom. Took me maybe 30 minutes.

 

[Rolocado]

Got this sucker in there.
Wasn't too bad of a job working from the bottom. Took me maybe 30 minutes.

View attachment 1504072

Work better now?

 

[dlmcgehee1]

Work better now?

Indeed.

 

[Rolocado]

Indeed.

View attachment 1504365

Did you have to move the fan shroud at all? Or just have to pull the PS pulley to get to it?

 

[dlmcgehee1]

Did you have to move the fan shroud at all? Or just have to pull the PS pulley to get to it?

I just pulled the bolts on the PS pump, moved it up a little.

 

[Rolocado]

I just pulled the bolts on the PS pump, moved it up a little.

How the f$%k did you get this out the bottom? I have 3 or so cooler lines in the way.

 

[dlmcgehee1]

How the f$%k did you get this out the bottom? I have 3 or so cooler lines in the way.

Well, from what I remember, I had to rotate the alternator just right to get it out.

 

[flintknapper]

How the f$%k did you get this out the bottom? I have 3 or so cooler lines in the way.

Follow the cooler lines back to where they are held in place by a clamp, loosen or remove that bolt so the cooler lines can be pushed out of the way. Turn the alternator sideways and sneak it past the lower radiator hose. Its tight...but its doable. Did mine that way.

 

[RobRed]

did mine through the bottom as well.