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´68 SDV not charging

Started by Kell Oskarsson, May 02, 2016, 10:37:50 AM

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Kell Oskarsson

All,

I´m continuing to have electrical problems on my ´68 SDV. Did a bit of work this winter, had the radiator re-cored, new thermostat, and a bit of underhood TLC. As I had charging problems earlier and an occasional flicker of the GEN light, I removed the alternator and had it checked by a specialist. He replaced the brushes, bench tested and concluded it was operating fine.

Then, last week, I had finally put everything back together. She started and ran OK, but no charge from the alternator (when running, I just got battery voltage when measuring). I then replaced the voltage regulator, which appeared to be as old as the car, with a new one from Standard (part no VR103). Started her again, some charge (13-something) but crackling noise from the new VR and a faintly illuminating GEN light. Then the VR fell silent, again no charge and a constantly lit GEN light as long as the car was running.

I removed the alternator again and took it back to the shop once more this morning. It still tests OK but appears to put out sixty-something amps. It is a rebuilt unit (see pic) and there are no output stampings visible on the casing anymore. My car has factory A/C and hence would have originally come with either a 55A or a 63A alternator. The specialist thought it unlikely that the output would be enough to fry the VR, however.

I´m planning to get a solid-state VR this time, possibly the last one was defective. I´m guessing it´s either that or the wiring between the VR and alternator. Any other ideas? Or can any of you identify the amperage rating of my alternator from the pics?

Many thanks,

Kell.
Kell Oskarsson

1968 Sedan de Ville
1979 Chevrolet Caprice Classic Sedan

bcroe

When I had that problem, I got a 76 electronic internally regulated alternator
which bolts directly in.  But it must be rewired, throw away the mechanical
regulator and some wires, reconnect 2 wires.  At that point there is only one
"part" to fail, and less radio interference.  This has been discussed a few times. 
Bruce Roe

Kell Oskarsson

Bruce,

would you happen to have a parts number for the replacement you used?

Thanks,

Kell.
Kell Oskarsson

1968 Sedan de Ville
1979 Chevrolet Caprice Classic Sedan

bcroe

Quote from: Kell Oskarsson on May 03, 2016, 02:32:30 PM
Bruce, Would you happen to have a parts number for the replacement you used?
Thanks,    Kell.   

Sorry, I just grabbed some alts at the junk yard; also grabbed the 2 pin
connector which is different from the external reg type.  About any 76-79
Buick/Olds larger alt ought to work.  Cad did go a little crazy with physically
bigger 100A alternators that won't bolt in about this time.  I pull the excess
wire to streamline things, but there is also an adapter that plugs into the
harness (in place of the mechanical reg).  Bruce Roe

Kell Oskarsson

Thanks Bruce, I´ll keep that option in mind. Should have a new VR by next week, and maybe that will solve things for now.

Best,

Kell.
Kell Oskarsson

1968 Sedan de Ville
1979 Chevrolet Caprice Classic Sedan

Scot Minesinger

Keep the std alternator and voltage regulator.  It is unlikely that the reason you are not charging is because a conversion to an internally regulated alternator would solve the problem.  It will make it worse because you will have to re-wire, which makes tracing a wiring problem even more difficult.  Likely you have a wiring issue (short, bad connection, or bad ground) somewhere and it needs to be searched and found.  All three of my 1970 Cadillacs work fine with same system as yours.  In fact one was converted to internally regulated alternator and I changed it back.

My first place to look is the grounds.  There are two I think in close to alternator, make sure those are good.  Make sure your connections (those two on back of alternator) are good, often that connector is so cheap it makes a poor conduction connection.  The poor ground will make the generator light glow slightly.

You are going to need to trace this issue out, unlikely to be a component problem unfortunately.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Kell Oskarsson

Thanks Scot, that sounds like good advice. The alternator connections do look shoddy - wires as old as the car and simple spade connectors for the F and R terminals. Once I have a fresh VR I´ll hook everything up and go hunting.
Kell Oskarsson

1968 Sedan de Ville
1979 Chevrolet Caprice Classic Sedan

Dan LeBlanc

Is it possible that one of those spade connectors is shorting on the alternator case?  I'd re-wire in a proper connector. I think it is still available.
Dan LeBlanc
1977 Lincoln Continental Town Car

Jeff Rosansky CLC #28373

Have someone watch your generator light while you wiggle the wires. Probably a weak connection on a spade clip
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Kell Oskarsson

OK, progress report: I hooked up the new (solid state) voltage regulator and put everything back together one more time (boy, that alternator is truly a PITA to install, especially the bottom bolt and spacer). It appears to work, she is charging - cranking out some 14.15 volts. Alas, the GEN light refuses to go out for some reason.

I´m planning to go out and get my tags tomorrow - can´t wait to drive this thing again after a 2-year stop! After that I´ll start chasing the GEN light and the other electrical gremlins, such as no power windows, a/c or radio.
Kell Oskarsson

1968 Sedan de Ville
1979 Chevrolet Caprice Classic Sedan

bcroe

If its maintaining 14V with some load (headlights, blower), you are charging.  The
other issues you mentioned could also relate to the GEN light.  That light expects
to have 12V from the ign on its other end, and another wiring issue affecting
that could be the problem.  Fix everything you know is bad and see what happens. 
Bruce Roe

Jeff Rosansky CLC #28373

I am not sure on your year, and in fact I would have to look for mine, but I think the trans fuse will also effect the charging. Look in your manual to be sure.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

Scot Minesinger

Yes, Jeff might be right about that, check all your fuses, as sometimes a blown fuse causes the light to glow even when it charges fine.  On a 1972 Eldorado I was working this was the case (trans fuse), and also gas gauge would not work.  Solution was to replace engine bay wiring harness with decent used and fix a lot of shorts under dash caused by previous audio workers.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty