I have a puzzling issue that seems to defy logic. I've tried to replace my '64 Wildcat's original (not sure if it is OE or later replacement so it is original to when I purchased the car) 3-wire alternator twice with high quality reman alternators and both times the new alternator did not charge. The original alternator functions fine (sytem voltage when running is about 14.3V) but has bearing noise. The first reman I tried did not charge and the idiot light came on. I returned it to the dealer and they tested it and said it was OK. I reinstalled it and no go, so I returned it for another from a different supplier. Same deal, no charge. System voltage was the same as battery voltage when running. I reinstalled the original alternator and all was fine. All are externally regulated, 3-wire, and are direct bolt in. The regulator is the solid state type. To make it even more puzzling I gave the second alternator to a friend to try in his '69 Olds Cutlass and it works fine. I am getting ready for another drving season and don't want to have a failure on the road. Has anyone else had this or a similar problem wih their '64?
Sounds confusing enough...lol. Are you sure you have power to all three terminals with it running? I am assuming that the small plug in is identical on all three and you are positive that it is an external type,so something sounds funny. Some of them had to have a ground from the small stud on the back of them and some never used it,but I am not sure what to tell you other than try grounding it from the stud and make sure you wiggle the small plug in while it is running to assure correct contact. I am also assuming your plug on the voltage regulator is clean if it charges with the old alternator. Use your test light to check your connection on the alternator and make sure you show power on all three.
Another option is replace the bearing (and the brushes while apart) on your original alternator. o No:
There;s a thing called "tickler voltage" or "excitation current". This is a small current is applied to the rotor brush, the alternator will not charge without it. The voltage is usually fed to the alternator through the idiot light bulb. Does the idiot light come on when the ignition is turned to the "on" position? I've seen alternators that have a small resistor, usually 10,000 ohms or so, inside to provide the excitation voltage usually for cars that have an amp gauge instead of an idiot light. I ran into this problem on a 422 I restored a few years ago. I wish I could remember exactly how I fixed it. I know I could turn the alternator off and on by touching a high ohm resistor to 2 of the terminals. If I remember how I did it I'll let you know.
Thanks for the advice and tips. The idiot light does come on with the key on, engine off. Rebuilding the original is possible but I am afraid something might get damaged during the rebuild and then I have no working alternator and nothing to compare to. Also it may be necessary to go to a lower output alternator this spring for other reasons I won't go into now.
It is a common practice for some rebuilders to use the "exciter" regulator on one wire aftermarket rebuilds. This sounds strange because that external type should be charging about 14-15 volts just idling. Are you sure the ignition switch is in good shape?
I get 14.3V at idle (~800 rpm) and about 14.5-14.6V at about 2000 rpm. I've checked the function of every alternator with both a SS regulator and the original (when I bought the car) adjustable type. I have the same results with both. The only thing I haven't tried is to check the function of the original alternator in a car that the reman alternator functions in. I have zero electrical issues with the car when running the original alternator. It's too cold right now to do any more testing (10 degrees this morning in NC). Actually the car is fine as it sits but I want to replace the alternator for reliability purposes, before it breaks down and I can't find another alternator to work on the side of the road.
That would be good voltage if you have a solid state regulator or an alternator with an internal regulator. Is it possible they are selling you one wire/internal regulated alternators? Does the voltage stay up when you turn your lights on? You can apply excitation current to the alternator by applying switched 12 volts through a 100 ohm resistor to the "F" terminal on the alternator. You can also use a small bulb, like they use in a dash cluster in place of the resistor. Or, you can check for the excitation current by checking the voltage at the "F" terminal with a volt meter, it should read 12 volts. Don't check it with a test light. Ok get this. On my 87 turbo Regal the excitation current is supplied through the idiot light bulb, so, if the bulb burns out the alternator stops working. Now the alternator is not working and the bulb is burned out so I don't know there's a problem until my battery goes dead. Great design!
The reman alternators are direct fit and are the 3-wire type. The fact that the last reman I tried didn't work in my car but worked in my friend's '69 Olds makes it all the more puzzling. It is as simple as dropping in a reman doesn't work and putting the original back in works. Same connectors, wiring, regulator, eveything but the alternator (I do swap the pulleys a mine is for an AC car an has two grooves but the diameters are m/l the same). As a test I have my friend's OE alternator from his '69 Olds to try in my Buick. I'll try this one with the Olds pulley.
Try the new alternator in your car with the voltage regulator out of the Olds. Hey, I'm running out of ideas.
I tried my friends OE Olds alternator date coded March 1969 in my Buick and it worked fine. Voltage at idle is 14.2, same as the alternator that was in the car when purchased. This is the first alternator I have found that will work. Oddly enough the Buick alternator is date coded July 1969. Obviously it was a new or reman replacement sometime in the past 50+ years. Current plan is to rebuild the Buick alternator while the Olds alternator is installed.
As others suggested, I decided to rebuild the alternator that came on the car when I purchased it in 2010. After disassembling the alternator it was apparent that the previous reman or rebuild was half-a$$ed as they soldered new leads onto 4 of 6 diodes (blue arrows). The two that had the OE leads (red arrows) were pretty ratty. One lead actually broke off when I pulled it from the stud. Seems like I got to it just in time. After fully diassembling and cleaning I pressed the old diodes from the rear case half and the heat sink with a 3/8" deep socket and bench vise. The new diodes were installed using a modfied (and now ruined) 1/2" deep socket with a notch cut in it to clear the leads. Again the vice was used to press the diodes. After installing the diodes negative in the case, positive in the heat sink, I installed a new bearing, capacitor, and brush holder assembly in the rear case half. New bolts and insulators were used throughout except for the capacitor lead insulators which were not in my kit and had to be reused. It seems every "kit" I buy is missing something. Moving to the front half, I pressed out the rotor and replaced the ball bearing and retainer. I polished up the slip rings with 400 grit sandpaper and pressed the rotor back into the front case half. I reassembled the two halves and painted it with aluminum paint being sure to keep the mounting surfaces bare for a good ground. I also painted the fan and pulley with satin black. Once dry, I reinstalled it into the car, connected the wires and battery and fired it up. I got 14.2V at 800 rpm and no noise whatsoever. I'd say I am good to go for years to come. One thing for sure is that you are better off rebuilding these components yourself instead of buying the "reman" units as they only replace what they absolutely have to for proper function. Total cost was $42 for the rebuild kit and can of aluminum paint.
Yeah, the same sort of things happened to me on a '63 Riv. Supposedly the customer had his "Chrome" alternator rebuilt & it stopped working. Since time was running out for my move from my shop I got a rebuilt alt. Installed & as you it didn't work. Now on a Riv. the engine compartment, especially with A/C, is tighter than your Wildcat. One A/C line has to come off. There was no Freon in the system so that wasn't a problem, just replace the o-ring. Got another alt. same problem. Same after four rebuilt s. Now you start doubting your own ability's. Been doing this for yrs. & have NEVER had such problems in the past. Finally disgusted I tested his "Rebuilt alt. & did the same. Rebuilt it myself. Now the alt. works as it should, but it's not charging correctly. This now had all to do with the regulator. The reg. was a new A/C Delco. Replaced with another A/C Delco. Same problem. Got a new SS reg. same problem. Finally after four regs. I took the one of my Riv. & NOW EVERYTHING works as it should. Got a cheaply made SS reg. from a diff. supplier & EVERYTHING works as it should. Why do we have to go through this with these parts suppliers??? It didn't use to be this way until China got involved. How much time & $$$$$ did it cost me in the end??? I'm basically retired now, although I still have lots of work to do, I only get my parts from a dealer. Most of the time they work as they should & I'm not WASTING my time any more. If the customer doesn't want to pay the price he is FREE TO GO SOME PLACE ELSE. Tom T.
Tom, I am glad to hear I am not crazy or the only one this has happened to. I never found the underlying cause for the two remans not working but now have piece of mind that I won't get stranded with a dead battery.
I assume you put an insulator on your capacitor to positive heat-sink connection(pic #4)ou: It's very common to see the soldered diode leads on rebuilts.I always replace them myself but most mass builders wont due to the labor time involved.And Tom's right,good functioning regulators for these are a bitch to find anymore. One thing I ran into was the ohm reading between the 10 dn and 10 SI units is different.That initself will cause problems if not paired with the correct regulator.That's why so many IC replacement regulators apper to be nfg...it's actually the wrong rotor.
Yes, there's an insulator on the capacitor lead. As there wasn't one in the kit I had to reuse the originals. Thankfully they were in good condition. That pic may have been taken before I realized there was something missing from the rebuild kit when I compared what I had to the service manual. The original regulator still works but I replaced it with a SS regulator thinking that was the reason why the reman alternators didn't work. Another myth I busted is that it will charge with a burned out or missing idiot light. Maybe that is different from newer models?
Does the idiot light come on brightly with key on, engine off? It shouldn't, it should glow dimly. If it comes on brightly, usually its the regulator that's at fault.
There's no glow at all from the idiot light with key on, engine off. It could be that someone replaced the bulb with the wrong one? Many will fit the base but they have different watt ratings. I may have to pick up the correct bulb and give it a try.
