Continued issues with 1968 Olds 442 Charging system,

Maintenance/Repairs
81

I have actually put in a secondary fuel filter in-line just before the fuel pump. It is the ind that is cylindrical, ape 2 inches in diameter, and I chose the one with the transparent housing so I can see the fuel. The only think I notice in that is the fuel turns kind of orange-ish after not having run for a week or more. Either that is the normal color of gasoline when it is aging, or the filter is capturing some of the small rust particles, and when the car is shut off, some of those come off of the filter material and become resuspended in the gas in the filter. Either way, I’ll change that out soon too. My purpose was to have that to monitor the condition of the fuel coming through the fuel lines from the tank and to the carb. Once it seems as if all of this gunk has worked its way through the system, I’ll pull that off and replace the hose with a new style fuel hose (better rubber than the stock grade).

I picked up some very good, thick, 100% copper couplings to put on to the ends of the wires. I have done this for the 2 ends of the wires going onto the horn relay (the 8GA wire coming off the alternator, and the new 6GA wire I will connect to the battery (+) terminal. The guy at the store accidentally cut 6GA wire for one of the segments I asked for (wanted 2 different colored insulation), so now I have a super wire going to the battery. The mulitmeter reads 0.1 ohms from the BAT terminal on the alternator to the end of this wire (on the other side of the horn relay; I am measuring total resistance through the wires going from the alternator, through the horn relay and on to the battery). This is as good as the resistance just going through the wires themselves, so the connections are very good.

I need to get a second coupler to connect this 6GA wire to the (+) battery terminal, as I have decided to hook it up a bit differently than I originally planned. This should eliminate all wiring problems in this circuit (I hope).

It’ll be a couple more days before I am ready to fire it up again, so I’ll relay (pun intended) the results to the group at that time.

Have a good evening

Cryoman

82

The resistance of the new wires is less than .1 ohm. If you touch the meter probes together you will most likely see the same resistance. Unless you have a precision meter you are at the limit of the meter.

I still don’t have a good understanding on how your ammeter is hooked up to the charging system. From what you describe on how the new wires are run the meter doesn’t seem to be in the circuit.

83

Cougar-

I disconnected the ammeter. That is the confusion. Prior to doing this, the wire from the (+) battery cable went straight to the input of the ammeter, and the return wire went to the horn relay, making the connection to the wire from the BAT terminal on the alternator, albeit indirectly.

Sorry for the confusion.

And yes, it seems that I am now at the limit of the meter.

Another thing to note is that the original alternator put you 37 amps. The new alternator is apparently a 55 amp unit. I guess the actual amperage is controlled by the voltage regulator, if I understand how the systems works (which I still cannot say for certain that I do). I need to do some more reading. I’m trying to simultaneously learn, troubleshoot, and repair. At least I feel that the alternator can handle the system. The car never had AC, so it didn’t have an excessive current draw. With the changes over the years, some of the wiring was in need of attention, not to mention that nearly all of it is original, and after nearly 50 years, none of us are quite as handsome as we used to be (well, speaking for myself…)

I must say that I have been interested for a while in learning more about electronics, going as far as getting an electrical breadboard, jumper wires, a good text on circuitry, etc. Worked on that about 2 years ago before getting sidetracked. Unfortunately for me, when I took 3rd quarter physics in college (electricity and magnetism was a big part of the course), I was also studying Japanese, and that consumed much of my study time. I didn’t learn as much as I wish I had, and now have to catch up. At least I am still interested and having fun, except when I get stuck…but ultimately that’s how we learn best.

Enough philosophizing for now…

Good night.

Cryoman

84

You can buy a “one wire” replacement alternator and all your charging problems go away…

85

There are no more charging problems, the system is working like it should.

Thanks for clarification on the ammeter. The high amount of voltage drop you first saw may have been due to that being in the circuit.

The alternator has a battery “sense” lead that ties to the battery and it tells the voltage regulator what the charge status of the battery is. If the battery voltage is low due to current draw on the battery from loads the voltage regulator makes the output voltage of the alternator to higher to meet the demand. If less current draw is needed from the battery then the regulator backs down on the output from the alternator. It is a balance to keep the battery at a normal charge level. The battery warning light passes current to the exciter of the alternator so that light needs to work in order for the alternator to work.

The alternator you now have should be fine for the amount of current load you need to supply on the car.

86

The good news is that at least I got to drive it tonight. Now I remember why I am putting myself through this.

Here is the latest…

I installed the last of the wires. 6GA wire going from the horn relay contacts to the (+) battery cable. The alternator wire hot connection sits atop of this connection, almost like a direct connection between the two. It was not originally wired this way, but the original wiring was so that these 2 wires were adjacent to each other connected to the same piece of metal…nearly like they are now. The horn relay has 2 places where wires connect that are not part of the horn circuit. In fact, the original wiring diagram has all of the wires connected at the same point, so I don’t think this is a problem.

Here is the funny part, and I had not noticed this before, so I think this is the first time this has happened. When I put the red wire of the Fluke multimeter on the BAT terminal of the alternator, and the black wire on the (+) battery terminal, the voltage is now in the range where others have said it should be…around 0.1. However, when I make this connection, the meter (having an automatic switching function) reads AC voltage! When I test the battery itself, it is DC voltage, either with engine running or not. Does this make any sense to anyone?

Unfortunately, I can only declare partial victory. The GEN light still comes on at low RPM, and the battery voltage under these conditions drops into the 12.3 - 12.6 range. Definitely below 13.

Another thing is that after having driven it and parking it in the garage, upon immediately reading the battery voltage with the car idling, the voltage across the battery terminals was just above 16.0 (low 16s). I have read, and heard on this forum that such a voltage is a bad thing. Might this just be due to me driving it and wearing the battery down (all of the driving was in the neighborhood, about half of the time at speeds where the GEN light was on.

I re-started it a few minutes later and that was not the case. IN the 14s, like it should be. I have the idle when in Park set so that the voltage is in the range where the GEN light does not come on. When I put it in gear, the RPMs drop to the point where it goes back to the situation resulting in the GEN light coming on and the V across the battery being in the mid-12 range.

I think, just to cover my bases, I’ll get another new voltage regulator and try that.

As I said before, life could be worse.

Thanks again, and I’ll check in later.

Cryoman

87

The following is straight from the original shop manual. I wonder if the contacts of the lower set are malfunctioning. Just wondering.

Voltage Regulator
The voltage regulator limits the voltage of the electrical system to a specified maximum. The contacts of the voltage regulator oscillate at a high speed, opening and closing the points. This action intermittently introduces resistance into the field circuit, thereby reducing voltage.
The voltage regulator has a double set of contacts to regulate voltage. The lower set of contacts limits voltage at low generator rpm. Vibration of the lower contacts intermit- tently inserts a resistance in the field circuit. This resistance is satisfactory at low rpm; however, when the rpm is in- creased the lower set of points can no longer control the voltage and the upper contacts close. A vibrating action takes place on the upper set of contacts which intermittently grounds the field to control voltage to a safe value.

88

The alternator both charges the battery and supplies power to the cover the car’s electrical load at the time. The power & voltage output of an alternator depends primarily on the rpm (of the alternator pulley) and the field current. The voltage regulator measures the output voltage and adjusts the field current either up or down to accommodate the rpm and the car’s electrical load. If the “gen” light comes on, that usually means the voltage regular can’t meet the total power needs (for charging and usage) at that rpm b/c it is already at the max field current. Most common causes are the alternator pulley isn’t spinning as fast as it should due to slipping or the wrong pulley diameter. Others are high current loads on other electrical system, and faulty alternator diodes. Alternators have 3 or 4 sets of coils and diodes, and if one fails, 3 still work. But 3 isn’t as good as all 4 working, and that could cause this symptom. If the voltage regular isn’t accurately measuring the alternator’s output voltage, that’s another possibility.

89

Here is the entire paragraph from the shop manual. Notice the mention of DC. Now, the use of the term Generator seems to appear throughout the manual, and I had a previous discussion with others about whether this car has an alternator or generator. I don’t understand the difference…something to do with the…never mind. I just don’t understand.

Voltage Regulator
The voltage regulator limits the voltage of the electrical system to a specified maximum. The contacts of the voltage regulator oscillate at a high speed, opening and closing the points. This action intermittently introduces resistance into the field circuit, thereby reducing voltage.
The voltage regulator has a double set of contacts to regulate voltage. The lower set of contacts limits voltage at low generator rpm. Vibration of the lower contacts intermit- tently inserts a resistance in the field circuit. This resistance is satisfactory at low rpm; however, when the rpm is in- creased the lower set of points can no longer control the voltage and the upper contacts close. A vibrating action takes place on the upper set of contacts which intermittently grounds the field to control voltage to a safe value.
When the ignition switch is closed, before the engine has started, the indicator lamp lights to indicate the generator is not charging. The current flow can be traced from the battery to the “BAT” terminal on the switch, through the indicator lamp and resistor which is in parallel, and then through the voltage regulator contacts. From here it continues to flow on through the generator field winding to ground, completing the circuit back to the battery. Current through this circuit energizes the field windings sufficiently to insure voltage build-up in the stator windings when the engine starts. The voltage generated in the stator windings are then changed or rectified by the six generator diodes to a DC voltage which appears at the “BAT” or output terminal on the generator. The resistor allows more current to flow through the field winding to insure voltage build-up in the stator windings.

90

Thanks again, GeorgeSanJose.

I have this GEN light problem even when no electrical accessories are on (i.e. lights off, radio off, car has no AC, etc). I have had this problem with the original alternator, and 2 replacements since I began trying to solve this problem.

I’ll keep troubleshooting.

Cryoman

91

Jumping in late, Horn relay heats due to resistance, replace it if it is not bypassed, Check the battery for dead cells,

92

It is a newer battery. 1 year old. Might still be bad. I’ll check.

93

Battery checks out. Good.

94

"rectified by the six generator diodes to a DC voltage "

If it has diodes it’s an alternator.

The terms generator and alternator are kind of fuzzy and are sometimes misused.
Wikipedia: "Until the 1960s, automobiles used DC dynamo generators with commutators. With the availability of affordable silicon diode rectifiers, alternators were used instead. "

95

It’s a difficult electrical engineering problem to design a circuit to meter out varying amounts of current for the alternator’s field coils, especially if it needs to be a lot of current, which is does for an alternator. Sort of like trying to precisely vary the amount of water flow through a fire hose. Voltage regulators in those days didn’t even try to do that. Instead they just turned the flow either fully on or fully off using mechanical solenoid operated switches, and varied the on duration in relation to the off duration to precisely meter the current flow. If they wanted 75% flow, they’d turn it fully on 3/4 of the time, and fully off 1/4 of the time. If they reach a condition where it is on 100% of the time and it still doesn’t produce the desired charging voltage, the warning light comes on.

96

You asked about the Fluke meter reading AC instead of DC and what is the difference between the two. Batteries produce Direct Current which doesn’t change in voltage level. Alternating Current, like we use in our homes, does vary in voltage level. Household current (AC) varies in a waveform at a rate of 60 cycles per second.

Even though a alternator produces DC voltage there is a slight AC ripple voltage riding on top of the DC voltage. As long as the AC ripple voltage stays below .1 volt the battery is okay. When you fixed the problem with the excessive voltage drop to the battery the DC voltage dropped down (which is good) to a closer value that the AC ripple value is at. Now the meter sees the AC ripple as the higher voltage and as long as that stays below .1 volt you are good. Higher ripple voltage could mean some diodes inside the alternator have failed.

That fact that the battery warning light turns on at idle isn’t a real concern. The alternator can’t produce much power at engine idle speed, this is a normal condition. On the other hand seeing 16 volts across the battery is a problem and that will damage the battery over time. The battery sense lead connection may be bad or the voltage regulator may have an issue. If it was my car I would change out the alternator with one that has an internal voltage regulator and dump the old mechanical type. Though some stock purists may not like that.

97

Great news. I can finally declare victory!!! (I’m wanting to hear the trumpets to the tune of “TA DAAAA”).

The fundamental problem seemed to be the voltage regulator, despite having installed a new one.

I did a web search and learned that Wells makes a solid state regulator with the same housing style, plugs, etc for these old cars. Picked one up for $20. Fired it up this morning, let it warm up, kicked the idle down, and the GEN light stayed off! I measured the voltage across the battery terminals and it reads in the low 14s at all idles (not certain that the battery is fully charged currently…might drop into the 13s if so).

The resistance from the BAT terminal of the alternator to the (+) battery terminal now reads 0.0000 on my meter. Seems pretty good. Have the 8 and 6 GA wires directly in contact at the horn relay connecting the Alternator output to the battery positive terminal. All seems well.

Now…after 15 + years in storage, it is doing pretty well. Did have about $1000 worth of work done to it before trailering it to my new home, so it is at least drivable for the short term.

Next will be addressing the softness in the brake pedal (new front brakes, so there might be a bit of air in there), and the frost plug seepage. Really needs an engine overhaul, but…

If there is no apparent leak from the brake master cylinder, should I just leave well enough alone, or would it be worth replacing? Is that an easy job, or would it be best to hire it done?

Thanks so much to all of you for helping me through this. In hindsight, I’m glad the new regulator was a bit off, for it made me learn more about the electrical system, and also address a few other items that needed addressing.

Next time I run into trouble, I’m sure you’ll hear about it.

Best wishes to all of you.

Cryoman

98

Just a precaution here on your new heavy duty wiring. If you don’t have a inline fuse near the battery for the alternator charging lead and a short happens to get on that wire very bad things are going to happen real fast to the wiring and possibly other things on the car. You should have at least a 80 amp fuse installed to protect the wiring. The problem may never happen but if say an accident occurs and that wire gets shorted to ground somehow, stand back, a fire will take place before you can even get out of the car.

99

A point of clarification if I may. Currently, the hot air coming from the alternator terminates at the horn relay, and a second wire runs from that same terminal to the (+) battery terminal (to charge the battery as I understand it). Does this fuse need to be in the wire that is connected between the alternator and horn relay, or would it be OK to connect one to the wire going from the horn relay to the battery that allows the current from the alternator to get to the battery. I only ask because it would be a bit more safe to have it on the latter location, as that are runs alongside the inner fender for a short stretch, and placing the fuse there would keep is out of harms way.

Secondly, you say at least 80A. Does this translate to 80 or greater? I think the new alternator puts out 55A, and I assume this is the max output.

Just making sure I understand.

Thanks

Cryoman

100

Since your alternator seems to have a 55 amp output and the new wiring can certainly handle that current and more I would say a 70 to 80 amp fuse is sufficient for this case. The fuse should be placed as close to the battery as possible so you have the best protection possible for the wiring tied to the source of the power.

If this was my car I would eliminate the tie to the horn relay coming from the alternator. The main alternator wire should run directly to the battery (through a proper size fuse). Power connection to the relay should come from the fuse panel using a normal sized wire (16 gauge) from the horn fuse circuit. But it’s your car, not mine.

Good job on the fix and enjoy the nice sty’ln ride.