Alternator rating

[4silverado]

Is there an easy way to tell if truck has the 105 or the 145 amp alternator?

04 Silverado 1500 4.8L LS 2wd

Pulled positive cable off while running and truck died.

Battery is maybe couple months old.

 

[4silverado]

I think I answered my own question. Back when I got the truck, I’d run through all the RPO codes in the glove box. Mine has K68 > Generator 105 amp.

 

[ORVietVet]

Typically. the smaller engine and 2wd will lean toward the small amp alternator. BUT, stop pulling the positive battery cable off, while running. Worse case, can cause voltage spikes. There is a slim chance of that happening. You have a side post battery cable and during the removal, while running, you are removing and replacing contact to the circuit.

Use a DVOM to check the charging system.

 

[Tonimus]

Pulled positive cable off while running and truck died.
View attachment 3470

This wasn't good for the old 10si and 12si alternators. Plain ol' bad for anything more modern. Generally, if the truck is telling you it's not charging, it is correct. Even mostly dead batteries will allow the alternator to work.

 

[AuroraGirl]

I think I answered my own question. Back when I got the truck, I’d run through all the RPO codes in the glove box. Mine has K68 > Generator 105 amp.

you can tell by size, your alternator looks like this if its stock 105, mine is too (sad!)
But the case of the 140 is physically larger and the front air vents are differently placed, it will have a larger pulley too
The stator diameter can be roughly measured by the case diameter but you need to by able to eye the distance well on a ruler or tape measure

A- Air cooled
D- Dual fan
2 - 2nd generation electronics
44- 144mm stator diameter

The CS144 of the older trucks,
C-charging
S-system
1-first generation
44-144mm stator

The stator is the component with all the copper windings on it visible from the outside looking through the openings

 

[AuroraGirl]

Is there an easy way to tell if truck has the 105 or the 145 amp alternator?

04 Silverado 1500 4.8L LS 2wd

Pulled positive cable off while running and truck died.

Battery is maybe couple months old.
View attachment 3470

also yeah NEVER Pull the battery cable. your truck saying battery not charging is telling you its not, and a DVOM confirms it. the thing could have a bad excite wire, which can be bypassed with a 194 bulb base and a bulb (cheap at auto part store) you put one end on the batteyr positive an unplugged you would touch the L terminal

 

[4silverado]

I checked DMM and it was barely keeping it at 12.

I stopped and picked up a new alternator and on way home watched the voltmeter slowly drop to 9 volts before the truck shut off and wouldn’t restart. Ended up changing it on the side of the road and after jump starting it, it’s been running fine and charging at 14 volts.