PDA

View Full Version : Rebuild or replace an Alternator?



David_Jennings
12-22-2004, 15:49
My alternator suddenly stopped working. Any thoughts on whether I should simply replace it or rebuild it with one of those hi-amp kits? Thanks.

Ray Sharpe
12-22-2004, 16:04
Pretty easy to simply replace. You can purchase higher output alt's. for your truck. Just depends on how quickly you need your truck back.

David_Jennings
12-22-2004, 18:27
How high can I go without having to worry about the computer and other variables? Mine has a 105 amp, but there is a 140 that might fit. Thanks.

charliepeterson
12-22-2004, 19:19
Yes a 140 amp. will drop right on. The pulley diameter is critical though. If in doubt swap pulleys.

GMC Hauler
12-22-2004, 20:30
is the 140 amp a GM alternator?

johnny2can
12-22-2004, 21:28
Originally posted by David Jennings:
How high can I go without having to worry about the computer and other variables? To put your mind at ease... max amps of alternator (all other things being equal) will have no effect on your computer or anything else.

All equipment in your vehicle is powered at 12 volts... if you were to raise the voltage to 24 volts (common on the big rigs, I hear), you would fry everything. Increasing the amp capacity of your alternator will not increase the voltage.

The only reason to get a bigger (more amps) alternator is if you add more equipment (lights, heaters, electric fans, trailer/camper that charges off the truck, etc.)... more equipment sucks more amps.

Hope that helps.

Turbine Doc
12-23-2004, 06:35
Whatever you get make sure it has a replacement warranty GMs alternators leave something to be desired on longevity front, my 1st went at 45 K replaced with GM alt, now at 90K alt bearings making that familiar sound of going South, thought it was idler pully I replaced that no difference, a little WD-40 on alt bearing housing and noise went away.

damork
12-23-2004, 11:38
After 2 AC Delco failures, each at about 65,000 miles, I switched to a NEW Duralast Gold unit sold by Autozone. I've been running it just over a year now and it holds the voltage more constant than the Delcos did, they advertise to have more output at idle than stock units and that is what I have found. I believe the warranty is lifetime on the new units (those having Gold in the name).

A couple other sources are as follows:

http://www.alternatorparts.com

http://www.wranglernw.com/commerce/ShowCategory.asp?CategoryID=9

Billman
12-23-2004, 18:36
David

I replaced the original CS-130 alternator with a CS-144. It is rated for 200 amps.

The bigger case alternator will line up for mounting. You will need a different belt though.

I didn't need the additional amperage. I just put it on for the hell-of-it.

David_Jennings
12-24-2004, 06:59
I ordered a 140 amp OE Quality from Schucks. The parts driver failed to appear, so I bought the 105 amp unit, which was still higher than the stock unity. It has a three year warranty. It's funny; my truck has more trouble with truck stuff that has nothing to do with the diesel. Same thing with my 6.2. Happy Holidays.

GMC Hauler
12-25-2004, 18:34
I just got my laptop code reader program. One of the paramaters it monitors is actual engine RPM. My tachometer reads 200-300 RPM higher at idle than the computer says the engine is running. I know from the factory warranty information sheet that the alternator was replaced. I suspect the pulley is the wrong diameter. Can someone measure their pulley diameter and tell me what size it is supposed to be. Thanks

Billman
12-25-2004, 20:54
62mm rings a bell...