Alternator choice

[Fbks_Cruiser]

I put the buss bar very close to where the old voltage regulator was. Seems to work okay. I can definitely see the ammeter gage move, but just a little right after starting. (Needle never moves much if the charging system is working properly. ) My truck starts easily so the battery doesn’t get drained from excessive cranking. The alternator being a 12SI does a better job of charging at low speed so I don’t see the gage bump up when coming off idle. Before upgrading the alternator and installing headlight relays I had trouble with voltage dropping too low at idle if I had lights, wipers and heater/blower going at the same time. I could see a discharge on the ammeter at idle. Now, with the upgrades, I can have all lights (including 4 high beams since it a GMC), wipers, blower on high etc and ammeter stays rock solid. Voltmeter holds steady too.

[Rich72C10]

I might do what you did and then extend another junction from there to the firewall - thus keeping that OEM central location where the external voltage regular is (or after this mod - where it was at).

Then I could extend the +12v LMC Headlight hardness mainline to the new junction on the driver side (again where the external voltage regulator was). Thus removing it from the little junction on the passenger side. Hope that makes some sense!

[Fbks_Cruiser]

I would move the relays rather than extend the +12v lead. Keep it as short as you can. Run 8g wire from alternator to the buss bar at the front of the truck then another 8 or 10g from there to the junction on your firewall if you still want one there. Protect it with a fusible link.

[BRL]

I replaced my '69 alternator with some newer year internally regulated one after following the instructions...good post #18 Andy4639, but what's up with the red letters, you trying to blind me?

Anyway, I got a rebuilt 65 amp one from NAPA with a lifetime warranty and replaced it once for free due to noisy bearings.

That setup has been working just fine for 25 years at powering my awesome stereo and keeping the battery charged.

[ChevyRacefan]

Originally Posted by BRL

I replaced my '69 alternator with some newer year internally regulated one after following the instructions...good post #18 Andy4639, but what's up with the red letters, you trying to blind me?

Anyway, I got a rebuilt 65 amp one from NAPA with a lifetime warranty and replaced it once for free due to noisy bearings.

That setup has been working just fine for 25 years at powering my awesome stereo and keeping the battery charged.

I went with a 96 amp unit because of the stereo, the brighter than 1960's technology head lights, and the electric cooling fans, and dash cam.
Will it ever need the whole 95 amps, I doubt it, but it leaves some headroom so the unit isn't at the top of it's output .

[BRL]

I don't see anything wrong with a more powerful alternator, but don't know if it requires more horsepower to run or if it has thinner armature windings that may not last as long.

Of course with a lifetime warranty and a stored receipt it probably wouldn't matter.

It would seem that 65 amps does OK for my truck's requirements since I haven't added any other current drawing accessories at this time.

Guess I'm just trying to say that a person really doesn't need to get too caught up in the latest greatest most powerful $$$ model if one really doesn't require it.