Also check for a gasket between the distributor and the block. No telling what a previous owner may have done.

 

I did clean up where the distributor sits really well so I think it should be OK. I will get a new wire to replace the bad one at the battery, probably just replace the whole negative battery cable, and replace those last two fuses. Hopefully between that stuff, and cleaning up the connector for the VR as well as the terminals on the VR it will be better. Considering that the #3 terminal was so severely rusted and is apparently the one that senses the voltage perhaps that was the issue all along.

I will want to replace the VR, just have to find a good one. Summit has on by Tuff Stuff that has really good reviews and is made in the USA, but what throws me off is the low price of about $20.

Also, does having the generator light on when the car is running mean it isn't charging or simply that the battery may have been run down during the first run where voltage was all over the place. I hope that running it will charge up the battery and eventually shut the light off, but if I am misinterpreting the light perhaps I am going to end up killing the battery instead...

 

Gen light on means a problem in the charging circuit. That could be the alt, the reg, the wiring, or any combo of the three.First step is to repair or replace and clean any bad connections. Then you can test the three components.

 

Alright, so with everything reconnected and cleaned, I went to work with my limited electrical testing knowledge. Running at low idle it read fairly steady at 12.2. If revved to roughly 2000-2500RPM is went to about 14.2. I would have liked to get a read on the cold battery prior to starting, but the battery in the meter was apparently dying and gave some bad results. It read 13.68...

I will check again tomorrow morning after it has say and see what the battery is actually at with the car off. But, as far as I know the 12.2 at idle and 14.2 when revved is within reason isn't it? But even with those numbers the GEN light was on the whole time. Hopefully the battery is just not fully charged and running it will fix that...

 

Its time to see a picture of the wire hook ups at the alternator. Your voltage measurements seem wacky, try again.

 

Battery before car was started this morning only read 11.66. After started and settled into low idle was only 11.95 and seemed to very slowly drop, but that may have been due to a slight rpm decrease. When revved it still climbed up around 14. I think at lunch I will throw the new alternator on and do the test again. Pics of alternator and others below. One thing I recall reading is a battery below 12 volts is classified as dead. Is that right? If so how did the car start? Maybe I need a new tester...

 

Alright, I think I might have some useful numbers now. I happen to have a brand new battery for another car in the garage, and even on it the tester was saying 12.3V. I found a new tester on sale so I went and got it at lunch. It shows the new battery at 12.5V so maybe not 100% accurate but closer. Testing other things as comparisons it looked to be about 0.15V off.

So, with the new tester I went and checked the battery after it was sitting in the car for a few hours untouched, then started and checked the battery at low idle, revved and at the alternator all with the old alternator and regulator installed. Then I changed out the old alternator for the new one and ran the same tests. Below are the results:

Old alternator
Battery before start = 11.8
Low idle = 11.94
Rev = 13.4ish
At alternator = 12.4 (idling)

New alternator
Battery before start = 11.93 (probably irrelevant considering the car was just running 10 minutes ago)
Low idle = 11.57
Rev = no change, maybe an extra 0.02 or so
At alternator = 11.56, basically same as at battery

So, with that I think it is safe to say the "new" alternator is crap right out of the box. I didn't even try the new regulator considering how the voltage was all over the place and the noise it was making when I had it installed. I have a new solid state regulator coming from Summit, and I think I will try either Partsource or Napa for an alternator just so if it is crap returning is easier.

Is it possible for an alternator to weaken? Maybe the old alternator and the rusty regulator were the causes of my problems all along. Everyone kept asking are you sure you have 12V to the new HEI and I kept saying yes because it was a new wire right to it, but if the overall system voltage was weak, that answer was actually no. I have read that low voltage can kill things over time the same way that high voltage can. Does all this sound like a properly functioning alternator and regulator should be what the car needs or do these numbers maybe point to something else?

 

Lets check a few things. I see we have bat volts at alt post-good
connect volt meter to bat pos and ground on alt case- report finding
unplug reg. With key on, ground volt meter at bat and probe all 4 reg plug connections-report
connections are F-2-3-4 of the plug
With key off probe all 4 again-report.
Do you have a continuity tester? Can you make a jumper wire?
When you get back with the test readings we can move on.

 

Will go do that now. Just to clarify, for the first test do I attach the red lead to battery and ground on the case while off or running?

 

Off, but both way will tell something if there is a significant difference.So do it both

 

One thing to note - this i s all done with the apparently not working new alternator.

Red lead on battery, ground on alt case with while off = 11.8 (same as battery)
Red lead on battery, ground on alt case car running low idle = 11.56 (same as battery)

Regulator key off:
F = 0.0
2 = 0.0
3 = Seemed to bounce around but settle in around 6.5-7.0
4 = 0.0

Regulator key on:
F = 0.6
2 = 0.6
3 = Seemed to bounce around but settle in around 6.0-6.5
4 = 0.6

I think the new tester does continuity and I should have a jumper wire here somewhere. If not I should be able to make one.

 

3 should be battery voltage with key on and off. 4 should be bat volts with key on and 0 with key off. low voltage at 3 will cause an overcharge condition.(original problem?). Follow 3 to power source to find problem there. Or reconnect reg plug and jumper from bat pos to #3 then re test at bat with car running. one step at a time 4 will be next.

 

If you cant do continuity test we can still test F and 2 with a volt meter and a jumper.. Lets see what happens with #3 first.

 

I screwed the first test up, see below for corrections:

Regulator key off:
F = 0.0
2 = 0.09
3 = 11.74
4 = 0.0

Regulator key on:
F = 0.0
2 = 0.1
3 = 11.70
4 = 11.45

The battery was at 11.75 during these re-tests.

 

That sounds good. Test continuity at F and 2 by unplugging reg plug and alt plug. Test from F to other end of blue wire at alt plug then test 2 to alt plug white wire. If you don't have a continuity tester jump #3 to F and test for volts at other end and then jump 3 to 2 and test for volts.

 

It may sound like a dumb question, but is your belt tight? We are almost done and will determine if it is the alt or reg very soon which is good cuz its past my bed time.

 

Haha, I thought the same thing. It is snug. I dont see or hear any slipping. I will go do the continuity test, but that might end up being tomorrow morning.

 

OK. I'l be checking back during the nite. I usually only get up about 3 times a nite..I have no idea why. I'll probably be up around 4:30 or 5:30 for the duration of the day. Make a jumper wire so you can test the alternator. If it tests good the reg will be at fault.

 

Ok, will do. Thanks for the help. I am willing to do the work, just lack the knowledge sometimes, especially with the electrical stuff.

 

Continuity Test:

F to blue at alternator - 0.2, tester beeped when contact made
2 to white at alternator - 0.3, tester beeped when contact made

 

Good.
Next you will put volt meter on battery, note volts
With alt plug in alt and reg plug not plugged in start car
Put jumper from reg plug #3 to F. Note volts. Volts should rise at battery. Do not keep it connected for more than about 6 seconds or if the volts rise above 15 as this is running the alt at full output.Note if volts rise. If belt squeals during this test it may be a bit loose.
If volts rise, test volts at #2 when 3 and F are connected and running engine. note volts at 2 it should be 7-9 volts.
If this checks good the alt is fine and you should replace the reg.

 

Ok, just to clarify because I am nervous about running the car without the regulator plugged in - I am running the jumper wire from one location on the plug to another location on the plug, not from the plug to the regulator right?

 

Nothing to be nervous about. You may see a small blue spark when connecting jumper nothing to worry about. If you get a big white or yellow spark stop test. Yes jumping from #3 in reg plug to F in same plug. This is full fielding the alt and will produce max alt output. If you like you can do the jump without the car running just to see the spark. Just connect it for a second, don't keep it on until testing out put. If you have an ammeter on your tester you can connect it between the #3 and F without the car running. It should show 2-4 amp draw.Because your battery is a bit low is may take longer than 6 seconds for the volts to rise at the battery.when the jump is made and car is running. , so 6 seconds is just for safety. The point is you don't want it to be charging over 15 volts for any length of time longer than necessary to make the tests.

 

I hope you didn't get fibrillated or blow out your meter checking the amp draw Maybe you should have this thread moved to Electrical. You may get some better advise there. Joe P is excellent.

 

I haven't tried yet. Working from home so I was going to run out at lunch and see what I can come up with. I think it will go fine.

Actually, it looks like the multimeter can measure amps. So if I understand the manual, I would move the read lead over to the 10A port and set the dial to A and I should be good to do it this way. The dial also has uA and mA, but those are for smaller amp draws I think...

 

Apm test between F and #3 shows 1.93A. Not quite the 2-4A but with the battery only showing 11.7V at the time of the test maybe that is about right?

 

You do not want test amps with your meter as the load can quickly extend over the range limits and blow the fuse inside your meter. Also an fyi, checking amps require the meter to be in series with the wire your testing. You want to do all your trouble shooting with the volt meter. I moved the thread to the electrical forum.

 

Ok, good to know. I think we are nearing the end here anyway. If I understand right, we have confirmed the following:

-The alternator has power and is properly grounded
-The regulator plug is functioning as it should and has power where it should, when it should.
-There is continuity between the regulator plug and the two wires at the plug on the alternator.

So with all that confirmed, and considering the old alternator provided some charging, but still low numbers, and the new alternator provided no charge, I think it is safe to say the new alternator is a dud. I just am not sure if a failing or failed regulator can cause the low voltage situation the car has, or if the old alternator is to blame. Perhaps both? I have a new regulator from Summit on the way, probably here Monday. NAPA locally has either the 42, 61 or 63 amp alternators in stock. My car doesn't have A/C, but being that they are the same price, is there any harm in going to a 61 or 63 amp alternator.... if it is deemed that a new one is in order?

 

I'm just waiting to see if the new regulator fixes your issue.

 

That was what I was thinking too. I can install the new regulator and see what happens. If there is no change with the new alternator, I can put the old one back on and see what it does. If still low I can get another alternator and hope that does it.

I will of course wait to see if stellar has any further tests to try and narrow things down further.

 

The field draw test is good. Any of the alts 42-55-61-63 would all be fine. You may as well go with a higher one if yours tests bad. I would test the one in there now since you now know how. Jump #3 to F with the car running and check battery volts and then test #2 . I suspect you have a bad reg, but If it were me I would like to know about the alt. A bad alt can damage a reg so do the alt test first.No reason the blow another reg. At this point we know the wiring is good. We also know the alt field circuit is good and the diodes have no leakage or back drain. What we don't know about the alt is if the diodes are open or if the stator is sound, not being shorted or grounded. If the diodes are open or the stator is shorted or grounded you will very likely hear the alt make a growling or howling sound when you make the full field test. A charging alt will make some sound, but if the diodes or stator are bad the noise will be unusual and fairly easily detected.

 

Good point. I didn't think of the alternator damaging the regulator.

 

It is a good idea to be sure the reg is grounded before you connect the plug. I would advise that with any solid state reg.

 

Is that grounded simply by the three screws that attach it to the fire wall? If there is supposed to be another ground that might be an issue... cause I don't have one.

 

Yes grounded to the fender with the 3 screws. Some cars had a ground wire going to the screw that holds the capacitor and some had a ground going to the side of the reg. Usually the side ground was for when the reg was mounted with rubber bushings.You repaired the body ground so the 3 screws will be fine.

 

dedicated ground hole for delco reg. The hole on the side

 

Could the fact that the new alternator appears to not be putting out any charge be the reason that the new regulator was acting erratic or is that just what defective regulators do?

I don't think I tried the old alternator with the new regulator. I thought maybe it was worth trying that combination and if it works the new one from Summit could just be kept in the car as a backup. Based on the tests it did look like the old alternator was doing what it was supposed to, just at lower voltage but that could be due to the old regulator not working right.

It is worth noting that I wasn't replacing the old alternator because I suspected it was not working. I just planed to change the regulator and the alternator bearing sounds like it is starting to get a little noisy so I thought I would just change both.

 

The wires are good so a new alt and reg would appear to make you good to go. I would still change the reg plug, or put new ends on them. Let us know how it works out.

 

Well, because I can't leave things alone I went and tried the old alternator with the new regulator. The new regulator was buzzing away, at first, but once settled into low idle the generator light went off finally and it went quiet. I went and checked and had 13.5V at the battery and 14.0V at the alternator. Voltage did increase when revved, but the buzzing also came back and the GEN light came on so I didn't do much of that. But, I think that for sure means the new alternator and new regulator are duds. Either I have some bad luck or the quality of parts has really gone down hill, lol.

Oh well, I am happy with this. I think I will hold off on a new alternator for now and see what the new regulator does. Just for reference when its ready to go next time, I should have about 13.8V at the battery, and 14.0V to 14.5V at the alternator I think I recall hearing? I also checked the battery after I shut it off and it is up from the 11.70 to 12.2. I think some of that will be lost after sitting for a few hours, but it is still higher than it has been since this all started. Usually after running it was at 11.93 so I got some charging out of this too.

Thanks everyone for the help and suggestions, I really appreciate it and hope to finally have a problem free, fun summer with this car. I will let you know what the results are hopefully on Monday.

 

I got the new voltage regulator installed (a Tuff Stuff Performance 7635 in case anyone is having this issue after and wondering what part) and everything seems fine now. No generator light at all, no buzzing, volts were rock solid on 14 on the gauge in the car, maybe varied by 0.1 lower or higher. Even then it was a slow almost un-noticeable change. Certainly not like the last two where it would very noticeably be all over the place. I am surprised for how cheap the regulator was I was reluctant to get it, but all the reviews were good, and so is mine.

Cold in low idle I had 14.04 volts at the battery and 14.45 at the alternator. After a 10 minute drive with it warmed up I had 13.86 at the battery and 14.36 at the alternator. As far as I know, those are some standard good numbers.

Only time will tell if this fixes my issue with killing distributors and poor running conditions, but I did notice that slight bit of lag/stumble it had when punching the gas seems to be gone, but I only did it in park. I didn't do any hard driving today. Being the first drive since last year I just took it easy. I will try it again tomorrow with a harder acceleration and see if that feels any different. It makes sense that if I had low or maybe fluctuating low/high voltage it would explain a lot.

A huge thanks to everyone who walked me through this and helped with the testing. I am very happy to finally, at least for the time being, have this car up and running right. I think I will also re-check the timing one last time in case a stronger spark from proper volts to the HEI had an impact.