Snolab

My 69 442 has it's original alternator in it and it seems clear I am not creating any charge because the battery drains over time. I have only been driving short drives occasionally as I work on car. I know I need to test alternator to be sure but it also is making occasional high squeal noise as well. So question is should I replace (and with what) or should I have original rebuilt? Thx

rustyroger

First thing to do is get a multimeter and check the voltage across the battery terminals with the engine running. It should show something like 13.5-14 volts, even with the lights and other electrical consumers turned on.
If this makes the squealing worse then you may just have a loose belt.
Always check the simple and cheap things first, no point in buying a replacement or overhauling your old one if there is nothing wrong with it.


Roger.

pogo69

i would rebuild it it is a simple process that just needs a little patience and should only cost 20-30 bucks on avg

Octania

rebuild it or at least keep the core
internal regulated, right?
might be open face $$$ ?

Squealing can come from diodes dying also.

Charlie Jones

You mentioned "the battery drains over time". It's possible that the alternator may have a bad diode.
To test this, disconnect the negative battery cable and put a voltmeter between the cable and the negative battery post. If there is appreciable voltage ( one volt or more) then there is a drain on the battery. If there is, disconnect the alternator first. If the voltage goes away then the alternator is the problem. If not, try pulling one fuse at a time to isolate the circuit where the "draw" is coming from.

If you do need an alternator , I would suggest that you have the original rebuilt. "One wire" alternators are just plain "mickey mouse". and there is no advantage to them.

redoldsman

You will probably have to go to NAPA to get parts for it. I have rebuilt a bunch of these over the years by replacing the brush set and the front and rear bearings. I even replaced diodes once or twice. I remember several years ago going into AutoZone when the alternator on my 94 Suburban went out and asking for those parts. The woman behind the counter looked at me like I was from outer space. All they had was a rebuilt which I bought.

Snolab

Thanks for the replies. I have a delco remy 1100853 37A alternator. Put the meter on battery and clearly at idle or 1500 RPM the volts read 12.4 with power options on. So it's not charging. Only about 12.0 volts at regulator.

Also belt is tight and squeal intermittently seems to be internal. So while I'm not completely confident I think a good project sounds like learning to rebuild it.

redoldsman

I am not sure they come any other way but be sure and get the brushes with the holder.

Charlie Jones

It appears that you have a built in regulator on this alternator. If you plan on rebuilding yourself you may want to test the regulator before removing the alternator.
With the engine running, put a miniture screwdriver through a "D" shaped hole in the back of the alternator and contact a metal tab on the regulator. Make sure to contact the edge of the hole and the tab at the same time. The voltmeter at the battery should jump up to 14 plus volts immediately. If it does, the regulator is defective. If not the alternator is bad.
As mentioned before replace the brushes and bearings. Also replace the regulator if it tested bad. You also need to test the windings and the diodes for continuity and the diodes for reverse bias.
The 1969 Olds chassis shop manual should have detailed instructions on how to test and rebuild this alternator.

stellar

By all means, rebuild the original. Brushes come either as an assembly or by themselves. Parts should be available at a local parts store, unless you need a stator or field winding.