I’ve got a 1964 98. I’ve attached pictures below. I’ve only had this car a few months and the previous owner looks to have replaced the alternator, but the Gen light is still on. Looks like the battery cable was replaced as well. It’s still wired to the factory voltage regulator. I’ve been reading about different alternators on the forum and there is mention of 10SI and 12SI and that they require bypass of the regulator, but I can’t find any info on what mine is (ie internally or externally regulated), only that it’s a pathetic 61amps. Thanks for any help.

 

Which, going by the plug, yours is.

What kind of electrical load do you intend to put on this alternator? Even fully loaded as your car is, Olds and Delco-Remy engineering thought 61 amps was plenty. It's only going to supply as much as the car needs anyway.

If GEN light stays on above idle speed, time to have the alternator load tested. If it stays on with key off there's a shorted diode.

 

Yes it is external reg. It has been rebuilt so it may or may not be 61 amps. It may be less. If you want a higher out put capable alt use a 12SI 94 amp internal reg alt. Easy to wire up and a direct fit.

 

[QUOTE=drjaredshelton;1316824only that it’s a pathetic 61amps.
[/QUOTE]

Why do you think that's "pathetic"? Unless you have added a bunch of aftermarket electronics, that's more than enough. Non-A/C cars were fine with 37 amps. A higher output alternator isn't going to make your car run any better.
And the rebuilt alternator in your photos is a 10DN, which is the normal GM alternator for external regulator systems.

 

Perfect, thank you everyone.

Gen light is on while its running. Not after key off. I'm assuming that was happening before I bought the car and so the guy replaced the alternator. I know its brand new because its the only thing under the hood that wasn't completely caked with grease and dirt, lol. Maybe the voltage regulator needs replaced?

 

Could be the regulator, could be the wiring, could be that the rebuilt alternator is crap (it wouldn't be the first time).

 

Used to be the big cars didn't see the electrical buggering A-body cars did. Then the big wheels crowd discovered them and all bets were off. And your big Oldsmobile had 20s when you got it...

Jared, you got the 5 volume 64 shop manual, right? The electrical section should get you thru troubleshooting this problem. But first I would have that alternator tested. As Joe P says, wouldn't be the first reman that was bad out of the box. If alternator tests good, then it's time to look into the regulator and wiring.

Don't have my 64 books handy. I know 63 (Olds' 1st full year of alternator usage) had some type of relay in the charging system but that was eliminated for 64. Charlie Jones may have some insight, think he was a dealership line mechanic those years and knows these cars well.

 

Yep, didn't give me great info on trouble shooting it. Got car running again today and tested. Has 15.1V while running. Gen light is still on on the dash with all of the electrical turned off. Other than that, everything seems to work pretty good.

 

Idle was 15v. I got a new VR delivered today, so I'll see if that helps or not after install.

 

15v for any extended time will boil a battery dry. Good call on VR, sounds like that's where the issue is.

While you're about it take a wire brush to both battery terminals/cables and to the post and wires at the horn relay/junction block on driver fenderwell. Your big Osemobeel is now 57 years old after all, and no telling what kinds of electrical indignities it's been subjected to in that time.

 

Will do. It has a new battery and new cables all around too. I'll brush the relay. I am still having a short in the driver's side blinker somewhere between the fuse block and the light that I have yet to track down. Really hate electrical gremlins. I'm no electrician for sure.