Alternator / Voltage Regulator

[patrickt]

Originally Posted by Large Arbor

I am not sure what the ammeter actually did. I mean mine did not work and I have heard of other ERA members not having working ammeters Was it just for show? What current did it measure? Seems to me, voltage is a better indicator of what is going on with the charging system which is why I am doing the switch.

Phil

There is some misunderstanding about the ammeter in these cars. Of course, if it didn't work (meaning the needle was always just pointing straight at zero), then it's not much help anyway!

The ammeter sits between your battery, which is on one side of it, and the alternator and the electric load of the car, which is on the other side of it. When the battery is fully charged, and everything is running normally, very little current passes through the ammeter regardless of what sort of electric loads you have turned on (fans, lights, pumps, etc.). That is because both the load and the alternator are on the same side of the ammeter. As the load goes up (because you turn on your headlights, for example), there will be a momentary rush of current from the battery through the ammeter to help serve that load, but the alternator will then pick up the task and handle it -- so the ammeter needle will once again be close to zero. Likewise, right after starting your car, the battery will need some charging, so more current will be running from the alternator/load side of the ammeter to the battery -- but not for long. On a healthy battery this will only be for a short while and then the current will go back down to a dribble. Just because you have a 100 amp alternator does not mean 100 amps is always (or ever) going through your ammeter. Plus, most ammeters do not pass all the current through the gauge itself anyway. Only a portion of it actually passes through in order to be measured. Of course, sometimes ammeters fail -- and this is their weak point. If your ammeter somehow shorts itself to ground, then the full power of the alternator will ramp up to attempt to serve what looks like a big hefty load, but what is really just a short circuit. The larger gauge wire can carry quite a bit, and will make quite a mess, along with a fire. The ERA master circuit breaker will not help with an ammeter that is shorted to ground if the alternator is still turning and producing current; it will help to isolate the battery though. A voltmeter doesn't have this problem, as very little current is going to it and, if it shorts, it will just blow a fuse like a bad bulb can -- no big deal at all. I like my ammeter, and it's more sensitive to quick changes in load than a volt gauge. So, in that regard, it's more fun to observe and will tell you more if you are really familiar with it, your car's electric load needs, and the peculiarities of the gauge itself. But if you have a systemic problem with your charging system and battery, a volt meter will tip you off just as well. And volt meters are as safe, or safer; there is no argument there.

[PeteF]

I like the ammeter because it was original equipment on these cars, and I like to see when my battery is charging or discharging. I also have a digital voltmeter that plugs into the cigarette lighter port, for when I want to see voltage. You can get them on Amazon and some auto parts stores for about $15-20. Mine is made by Innova.

[DanEC]

Good post and explanation Patrick. On my 66 Corvette, the old factory engineers on Corvette Forum who worked for GM way back then have stated that what is commonly called the ammeter gage - is actually more accurately a "battery gage". It measures charge and discharge of the battery but not alternator amperage output.

[Large Arbor]

Thanks for the refresher Patrick. I knew the function (i.e. to measure current) but I did not know where it was measuring flow from. It seems to me the Voltmeter, while not period correct willl provide greater indication of whats going on with the alternator and voltage regulator. I know the things that draw load but its not much. My alternator is acually an 85 amp version so I would guess its putting out 60 most of the time (Cobra Valley version).. Eventually, I will push the amperage up on the alternator but for now the 85 A variety will be fine.

Phil

[DAVID GAGNARD]

Originally Posted by Large Arbor

Thanks for the refresher Patrick. I knew the function (i.e. to measure current) but I did not know where it was measuring flow from. It seems to me the Voltmeter, while not period correct willl provide greater indication of whats going on with the alternator and voltage regulator. I know the things that draw load but its not much. My alternator is acually an 85 amp version so I would guess its putting out 60 most of the time (Cobra Valley version).. Eventually, I will push the amperage up on the alternator but for now the 85 A variety will be fine.

Phil

Phil: not familiar with the type of alternator you have,but if it the old style Ford alternator, you can convert it for about 40 bucks and 3 minutes of work to a one wire alternator,eliminating the external voltage regulator....

I did this on my 65 fastback street car back around 1996 and all has been well ever since.....ran the same alternator set-up on my race car for 8 seasons with no problems.....

BTW: I'm using a 60 amp old style Ford alternator in the fastback.....it has an MSD ignition and one humungus OEM Caddilac electric fan and I have not had any problems with amps/volts or enough electrical power to run everything...check my photo gallery,I think there is a photo or two of the alternator with the one wire mod on it...

David

[DAVID GAGNARD]

found it,hope it attaches here..........

well, it looks like it will not attach,but there is a photo in my gallery of it......

[patrickt]

When I'm cruising down the interstate my total alternator output is right around three or four amps. That's it.

[RICK LAKE]

Large Arbor Phil before running off crazy, did we check a couple of things,
#1 Main wire coming off the Alt that charging the battery, does it OHM out? Is there a fusible link in the wire? With an 85 amp setup you should have a link. Slo blow of 100 to 125 amps in the power feed to battery.
#2 Volt meter gauge, SW sells one for cobras that matchs the others. You can get one with color also if you want.
#3 Under size pulleys on the motor of Alt? This will cause a charging issue with the car and not recharging the battery. Have you gone to a PEP boys or Autozone and have the Battery tested for Load? What is the CCA on it? how many year is the life? March pulleys cause this problem all the time.
#4 PA performance sell a complete kit for Cobras that bolts on and has a 95A to 120 amp rating. Buy the fusible link for the system. I run the 125 amp.
#5 IMO you are running to much ampage through the Amp gauge. It was never designed to handle this much. I can promise you that the plastic insolators are either melting or cracking from the load(amps) I went through this and almost melted my wiring harness under the dash and had a great weiner roast. Unhook the 2 feeds from the amp gauge and make a small jump line with 10 gauge wire and crimping clips. Cover the connectors with wrap. Need to loosen the steering column and the screws on the dash to get easy access.
#6 Ground wires on the car? You should have 3 wires. 1 to the frame directly and 2 to the motor, One directly from battery and one from frame to motor block
#7 Volt meters and Amp meters. The Orginial cobras ran like a 37A to 42 A alt. Not sure if they even had a generator on them at one time. Volt meters do give you a prewarning over an amp gauge. Amp gauge is in trouble and the wiring harness is starting to cook. We run from 65A to over 100 amps. We need the power for all the electrical things on the cars.
The VR should match the charging system. If you burn out another VR, If the system is charging at 50-60 amps all the time, you could have a failure of an electrical component like fan motors. You might want to check out #4 line for a better fix. The kits looks orginal with just a wire change. You can paint the VR box black if needed. Good luck with the car. Rick L.

[davids2toys]

Originally Posted by RICK LAKE

Large Arbor Phil before running off crazy, did we check a couple of things,
#1 Main wire coming off the Alt that charging the battery, does it OHM out? Is there a fusible link in the wire? With an 85 amp setup you should have a link. Slo blow of 100 to 125 amps in the power feed to battery.
#2 Volt meter gauge, SW sells one for cobras that matchs the others. You can get one with color also if you want.
#3 Under size pulleys on the motor of Alt? This will cause a charging issue with the car and not recharging the battery. Have you gone to a PEP boys or Autozone and have the Battery tested for Load? What is the CCA on it? how many year is the life? March pulleys cause this problem all the time.
#4 PA performance sell a complete kit for Cobras that bolts on and has a 95A to 120 amp rating. Buy the fusible link for the system. I run the 125 amp.
#5 IMO you are running to much ampage through the Amp gauge. It was never designed to handle this much. I can promise you that the plastic insolators are either melting or cracking from the load(amps) I went through this and almost melted my wiring harness under the dash and had a great weiner roast. Unhook the 2 feeds from the amp gauge and make a small jump line with 10 gauge wire and crimping clips. Cover the connectors with wrap. Need to loosen the steering column and the screws on the dash to get easy access.
#6 Ground wires on the car? You should have 3 wires. 1 to the frame directly and 2 to the motor, One directly from battery and one from frame to motor block
#7 Volt meters and Amp meters. The Orginial cobras ran like a 37A to 42 A alt. Not sure if they even had a generator on them at one time. Volt meters do give you a prewarning over an amp gauge. Amp gauge is in trouble and the wiring harness is starting to cook. We run from 65A to over 100 amps. We need the power for all the electrical things on the cars.
The VR should match the charging system. If you burn out another VR, If the system is charging at 50-60 amps all the time, you could have a failure of an electrical component like fan motors. You might want to check out #4 line for a better fix. The kits looks orginal with just a wire change. You can paint the VR box black if needed. Good luck with the car. Rick L.

Rick, I am confused on what you are saying in #6. Could you possibly break it down so it is less confusing? On my car, from the NEG term on battery, cable goes to frame. From the Pass side aluminum head I have a wire that goes to the metal tube behind the firewall. Also, if I remember correctly, I think I have a braided strap also going from the tranny to the frame.
I was thinking of grounding the drivers side head.

In addition, I plan to run the MSD box POS and NEG wire directly to the battery per the MSD tech department. They do not like those wires running to the frame or to the positive relay on the firewall which is my present setup. What do you or Patrick think of that?
Dave

[Large Arbor]

Gents, thanks for all the great input.

I took the alternator and VR together to a shop in Cincy that could test both together. The VR had died and was not working. The version of the VR was $9, a cheapie brand. I replaced it with a Motorcraft Solid State one that is working. The old one worked for 9 years so I have excluded other causes. The exising alternator is fine and if you go to the Cobra Valley web site you will see it puts out significant amperage at a low rpm. That being said, my future conversion will be as a result of adding things llike possibly heated seats (I do not have a heater), chargers for cell phones, and other current suckers.

The battery is brand new and puts out up to 800 plus cca. It is a red top Optima. I did order the SW Voltage gage (part 82391) to look period correct or close to it. I think the AMP guage just went bad. The terminals are fine and no burnt wires or ends. I will simply tape them up and tie wrap them out of the way. Another reason I want the volt meter is to see how much the fan drags the voltage down. I have toyed with running a higher capacity fan due to the sitting in traffic effect when its in the 90's.

All in all, thanks for sharing the knowledge.

Phil

[strictlypersonl]

See the ERA owner's section for a wiring diagram using a voltmeter.

More hints here:
erareplicas.com/427man/wiring/voltmeter.htm

[Kit Coyle]

My 1G alternator died. It was an "old style" autolite type 50amp with
separate voltage regulator. My replacement is a web purchased Pure Energy
brand...new but made in China. Still a 1G but more of a Motorcraft style
instead of the Autolite style pictured on their website. It works well...so far.
Would you trust this alternator and, if not, what do you suggest. In retrospect
maybe a Powercraft might have been better.

[davids2toys]

Awesome post Patrick I joke about you being the Guru, but you really are impressive!
So the fusible link wire is an excellent idea then for the exact reason you are saying protecting the MSD POS feed wire!!! In my car, that POS MSD wire cannot be longer than 5 feet from the box(under the glove comp) to the solenoid on the fire wall. Per your chart it should be good for 100 amps, that is awesome.
Thank you.
Just a thought... if you used just an inline fuse instead of the fusible link wire, it would be a lot easier to change out instead of being stuck on the side of the road. Also, your CB is the auto resetting type so if the scenario happen where the wire shorted out on the firewall, would it not keep on smoking and shorting due to the CB resetting itself?

[patrickt]

Originally Posted by davids2toys

Just a thought... if you used just an inline fuse instead of the fusible link wire, it would be a lot easier to change out instead of being stuck on the side of the road.

Yes, it would be easier to change. But the whole idea behind a fusible link is that it will only blow if there is something big time wrong and, most likely, it will require a tow back home and some time on the lift to find out why it blew. It is not designed, nor is it intended, to be a "quickie fixable" item. As I said in a previous post, I have never, ever, ever had to actually replace a fusible link in any of my cars... including the super-charged GTP that blew its oil all over the engine bay while I was driving, caught on fire, had flames coming out from under the hood, and every damn dashboard light there was started blinking and dying. Even with the car being a total loss from the fire, the fusible link still worked.

Originally Posted by davids2toys

Also, your CB is the auto resetting type so if the scenario happen where the wire shorted out on the firewall, would it not keep on smoking and shorting due to the CB resetting itself?

50 amps probably wouldn't even make the wire itself smoke, but there would likely be some smoke coming from around the fault location itself (because of the higher resistance on the fault). If I was really lucky, it might even "burn itself free" of the fault, like power lines will sometimes do with tree limbs, but probably not. The circuit breaker would be clicking on and off and I would be standing there with my thumb up my... thinking "hmmmm, I wonder what's wrong and what the hell is that clicking sound?" Then I would put my finger on the circuit breaker and feel it clicking on and off. At that point I would disconnect the battery via the quick disconnect gizmo on the negative battery terminal and the clicking would stop. I would then wiggle some wires, reconnect the battery, the circuit breaker would start clicking again, and I would call for a tow.

[davids2toys]

Sorry for the late post, been a totally crazy week here!

Originally Posted by patrickt

Yes, it would be easier to change. But the whole idea behind a fusible link is that it will only blow if there is something big time wrong and, most likely, it will require a tow back home and some time on the lift to find out why it blew. It is not designed, nor is it intended, to be a "quickie fixable" item. As I said in a previous post, I have never, ever, ever had to actually replace a fusible link in any of my cars... including the super-charged GTP that blew its oil all over the engine bay while I was driving, caught on fire, had flames coming out from under the hood, and every damn dashboard light there was started blinking and dying. Even with the car being a total loss from the fire, the fusible link still worked.

50 amps probably wouldn't even make the wire itself smoke, but there would likely be some smoke coming from around the fault location itself (because of the higher resistance on the fault). If I was really lucky, it might even "burn itself free" of the fault, like power lines will sometimes do with tree limbs, but probably not. The circuit breaker would be clicking on and off and I would be standing there with my thumb up my... thinking "hmmmm, I wonder what's wrong and what the hell is that clicking sound?" Then I would put my finger on the circuit breaker and feel it clicking on and off. At that point I would disconnect the battery via the quick disconnect gizmo on the negative battery terminal and the clicking would stop. I would then wiggle some wires, reconnect the battery, the circuit breaker would start clicking again, and I would call for a tow.

First quote:
Yeah, I hear you and I knew that...bad choice of words on my part. What I meant to say was that it would be a lot easier to change a fuse after the problem is fixed rather than replacing a fusible link

Second quote:
LOL...This is way to much thinking for me at a time when I could be doing some nice damage. I think I would rather just have something blow(fuse or fusible link wire). From your earlier post on that same line of thinking, why does ERA put that auto resetting CB there? Why would you want that trying to reset itself when obviously it had something bad going on to trip it off. I would think the kind that lets you reset it manually would be a better idea so you could try and troubleshoot it before trying to manually reset it? I'm thinking I might replace that auto resetting CB with the manual type you had mentioned.

[strictlypersonl]

A manual reset isn't a bad idea. Next time I order, I might make the change. A Bussmann 123B50-A2P-KA should be a direct replacement.

[patrickt]

If I was driving at night, and the engine was hot, so all my fans, both pushers and puller were running, and the head lights are on, and I stop the car and turn the engine off, so my fans and head lights are still drawing current from the battery, and then I reach down and push in the cigar lighter, I think that would be enough to blow the circuit breaker. I would instantly know that pushing the cigar lighter tilted the scale, so I would pull it back out and, after a few seconds, the circuit breaker would automatically reset and my fans and lights would come back on. Since it's dark outside, and I left my flashlight at home, that would be better than a manual reset. How's that sound?

[davids2toys]

Originally Posted by patrickt

If I was driving at night, and the engine was hot, so all my fans, both pushers and puller were running, and the head lights are on, and I stop the car and turn the engine off, so my fans and head lights are still drawing current from the battery, and then I reach down and push in the cigar lighter, I think that would be enough to blow the circuit breaker. I would instantly know that pushing the cigar lighter tilted the scale, so I would pull it back out and, after a few seconds, the circuit breaker would automatically reset and my fans and lights would come back on. Since it's dark outside, and I left my flashlight at home, that would be better than a manual reset. How's that sound?

Sounds like you should quit smoking cigars
Only kidding, I always have a cigar going while cruising around.
Seriously, why don't you try it and see if it actually proves out your theory. I suppose in that situation it would be a personal choice thing. I am thinking more of what I want the CB to do, shut down to protect. I just don't want it to be constantly trying to reset itself before I have a chance to fix what caused it to trip in the first place. My big concern is to avoid damage!

[patrickt]

Originally Posted by davids2toys

I just don't want it to be constantly trying to reset itself before I have a chance to fix what caused it to trip in the first place. My big concern is to avoid damage!

Ahhhh, what you want is a "Programmable Recloser." They're used in the power distribution industry and you probably have one outside your house or down the street on your circuit. So, if Sammy the Squirrel is unfortunate enough to put one paw on the neutral and one paw on an energized phase he'll blow the recloser and your lights will go off. But the recloser will automatically try and reset a programmed number of times, like three, to see if the fault is gone (because Sammy was skyrocketed over in to your neighbor's yard). Since the fault is gone, your lights come back on. But if it's something like a big tree limb that's still on the lines, then the recloser comes back on, and goes off, and comes back on, and goes back off, and comes back on, and then goes off and stays off until the tree is removed. That's what you want... but they don't make them for cars.

[patrickt]

Sammy in the news: Suicide squirrels driving utilities nuts - USATODAY.com