Which alternator is on my truck
 

2005 GMC Sierra 1500 2WD 5.3. Not heavily optioned. Power windows, door locks, electric fans. No Bose sound system, no power seats, no auto climate control. From what I have read, alternators are either 105, 140 or 160 amp. Which one do y'all think mine would be? Thanks.

Re: Which alternator is on my truck
 

Check your glove box for the RPO codes:

K65 - 105 amp dual

K68 - 105 amp

KG3 - 145 amp

Re: Which alternator is on my truck
 

Thank you. I'll look for it.

Re: Which alternator is on my truck
 

George I would guess the 145 Amp. I also believe some came with 160. Last I remember the connectors are different for each style. Even my V6 had a 145 amp, but it was a pure Chevy of course :D

Re: Which alternator is on my truck
 

160 amps were commonly found on 2500/3500 trucks. I know the four 2500s I had in this year group were all 160. The two 1500s I have are 145.

However, this is all assuming you still have the original installed or it has been replaced with the right one in the past. Belt sizes are sometimes different between 105 and 145/160

Re: Which alternator is on my truck
 

Belt sizes are sometimes different between 105 and 145/160[/QUOTE]

That's why I asked the question. About to replace both the serpentine belt and a/c belt. Many thanks for showing me what to look for.

Re: Which alternator is on my truck
 

If I'm unsure I buy both belts and return the one that doesn't fit.
I put the PN of the one that fits in my maintenance spreadsheet on Google Docs so next time I don't have to wonder.