Alternator / Voltage Regulator

[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

[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.

[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]

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

[patrickt]

Originally Posted by davids2toys

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

The MSD hot lead should run directly to the master circuit breaker next to the starter solenoid. The MSD negative lead should run to wherever your negative battery cable terminates. For example, on my car that is the passenger side cylinder head just across from the firewall. Regarding your grounding, ERA has a single black wire that is running from the passenger side cylinder head, where the negative battery cable is often attached, to the firewall. Many of us supplement the standard ERA grounding because the fans, headlights, and taillights all take their ground from the frame. That means all electrons must either go through that one little black wire, or find their way back home via some other way, such as motor mounts, emergency brake cables, etc. What I have on my car is a supplementary 4 gauge wire that runs from the negative battery post to the chassis frame, and I run a grounding strap from the intake manifold to the firewall. I've taken umpteen amp readings on all of my electric circuits and that system works quite well. Many cars do it exactly that way, so it's not like I invented it.

[davids2toys]

Originally Posted by patrickt

The MSD hot lead should run directly to the master circuit breaker next to the starter solenoid. The MSD negative lead should run to wherever your negative battery cable terminates. For example, on my car that is the passenger side cylinder head just across from the firewall. Regarding your grounding, ERA has a single black wire that is running from the passenger side cylinder head, where the negative battery cable is often attached, to the firewall. Many of us supplement the standard ERA grounding because the fans, headlights, and taillights all take their ground from the frame. That means all electrons must either go through that one little black wire, or find their way back home via some other way, such as motor mounts, emergency brake cables, etc. What I have on my car is a supplementary 4 gauge wire that runs from the negative battery post to the chassis frame, and I run a grounding strap from the intake manifold to the firewall. I've taken umpteen amp readings on all of my electric circuits and that system works quite well. Many cars do it exactly that way, so it's not like I invented it.

Well my car is half right then. My POS MSD wire goes to the CB on the firewall like yours. My battery is in the trunk so my negative BAT cable goes to the frame in the back, so perhaps I should run my MSD neg wire all the way to the back to where the NEG BAT cable is connected to the frame, or directly to the battery. I guess I could also get a long NEG battery cable and run it to the front and connect it to where yours is connected.
As I said, MSD instructions and their tech dept want you to hook both wires directly to the BAT. I told them my set up and they said that was NG.
Last I talked with them was last year...I think I will call them again.

[patrickt]

Originally Posted by davids2toys

My battery is in the trunk so my negative BAT cable goes to the frame in the back, so perhaps I should run my MSD neg wire all the way to the back to where the NEG BAT cable is connected to the frame, or directly to the battery.

Yes, that's exactly what I would do. And I would use a fat wire (single digit gauge) since the run is maybe a dozen feet or more.

[RICK LAKE]

davids2toys David I run mine MSD directly to the battery with a fusable link of 40 amps on the + side. I do have a master battery cut off for the car that kills everything but power to my ECU. There have been other threads on here about how much power a 6AL module uses. I am in the 8-12 amp range and the Spike of the system I have not done. If the module draws so little ampage from the electrical system, then why is 12# gauge wiring being used?? I had a problem with high resistance when I first finished the car. You need good grounds with FI systems. I moved the battery to the trunk and main connection was in the trunk. Problem was the motor and trans are isolated with rubber mounts. Yes there is a ground wire on the ERA but FI systems need more. If you do the bolts through the motor mounts and have clean areas of contact this will work OK. I overkill things. I Have 2 grounds to the motor. 1 to the block and one to the head R/S. It is important that the thread holes be clean and no paint on the ground areas. I have a Shelby block and heads of aluminum and it is not the best conductor of juice.
Side note for MSD, I mounted my unit under the glove box with my ECU for the FI system. The R/S foot ducting blows fresh air on both modules to help keep cool. I know that these MSD module gets hot. I had a failure of a new one from working on the car and welding to the frame without unhooking the battery. Good thing it was covered by warranty and fixed for free. I don't know if Pat is right or wrong, I followed the manual for installation, 15 years of racing with same box. Cap and rotor in the distributor, that's a different story, carry spares. Rick L. Ps I also have spare MSD and complete distributor and basic tools to install, just in case. Last note, I solder and climp connectors on my wire ends and use shrink tubing to weather proof sealing. I also use star washers that add bite to a connection and help reduce resistance there. Spraying a connection with grease, paint, undercoating, or sealer, The jury is still out on this. I do use electric dye grease on all my connections. It seals connections and no loss of resistance to that connection. It's a GM fix for years with out side connections under the car or truck. Good luck.

[davids2toys]

Patrick and Rick,
Turns out there is another No-No in my car. You are never to seal up the case ot mount the box upsidfe down. My box is mounted underneath the glove compartment upside down!
I spoke with the MSD tech dept yesterday about all of this stuff.
He said I could get away with upside down mount provided no exposure to rain or condensation because the moisture will have no where to go and the case will act like a bowl...this will cause corrosion.
For the POS and NEG 12 gage wire, they again recommended going directly to the battery with NO fuses or circuit breakers of any kind.
If lengthening the smaller wires you can run the same gage or step them up to 12 gage. If lengthening the The POS and NEG heavier wires, no option of keeping the same gage, must be stepped up to 10 gage.
Not being an electrical GURU by any stretch of the imagination, one thing I don't understand is that even if I step up to #10 wire, I will still have the original length of # 12 wire that I will be connecting to. Wouldn't this be a weak link now?
I tried to post the General installation Tips but it was to large. Below is page 8 of this PDF called General installation tips:


GENERAL INSTALLATION TIPS

MSD MOUNTING
MSD Ignition Controls are designed to withstand under-hood temperatures but should be mounted away from direct engine heat sources such as headers or manifolds.
The ignition control can be mounted in most positions except upside down. Mounting the unit in an enclosed area such as the glovebox is not recommended.When running, the housing of the MSD will be hot to the touch.When a suitable location is found, make sure the wires and harness will reach the coil and battery. Use the ignition as a template and mark the mounting hole locations. Remove the ignition and drill the mounting hole
locations. If extremely high vibrations and shocks are expected, use a set of MSD Vibration Mounts to help protect the ignition. The mounts come in sets of four;PN 8823 for the Blaster Ignition, MSD 5 and 6 Ignitions,
PN 8800 for MSD 7, 8 or 10 Ignitions.

Sealing MSD Units
While applying some type of sealant between the MSD case and base plate would seem to be smart, it is not recommended. All MSD Ignitions have a special water resistant treatment to prevent water damage. By sealing the base plate to the case the condensation and water that seeps past the cables is trapped in the unit which may result in corrosion. Always allow the unit to drain by not sealing the base plate.

WIRING TIPS
When making permanent electrical connections it is imperative that proper terminals, connectors and soldering be used. Using connectors such as MSD's Weathertight or Deutsch connectors provide positive locking, sealed connections. Never simply "twist and tape" wires together. Faulty wiring will result in ignition and electrical problems.

MSD Power Cables
The Power Cables of the MSD 6, 7, 8 and 10 Ignitions are the heavy (12 gauge) Red and Black wires. The Black wire connects to battery negative (-) or ground and the Red goes to battery positive (+). No switch or fuse
should be used. The Red wire must be connected directly to the battery
positive terminal or to the constant positive side of the starter solenoid.
The Black wire must be connected to the battery negative (-) terminal or to a good engine or chassis ground.
MSD offers a Noise Filter, PN 8830, for the Power Leads. This Filter goes inline on the power cables and will protect the Ignition from voltage spikes or battery failure. The Filter will also help eliminate a major cause of radio noise that may affect engine or other on-vehicle electronics.
NOTE: If you ever need to turn the engine over without starting it, disconnect the small Red wire on the MSD 6, 7, 8 or 10 Series.

Grounds
A poor ground connection can cause many frustrating problems. When a wire is specified to go to ground it should be connected to the battery negative terminal, engine block or a common solid ground on the
chassis. Always connect the ground to a clean, paint free metal surface and always have a ground strap between the engine and the chassis. Do not rely on solid engine mounts as a ground between the chassis and engine.

Wire Length
The power leads and the wires of the MSD can be shortened, however the correct connectors should be properly installed and soldered in place. If the wires of your MSD Ignition are not long enough for your application,
they can be lengthened if properly done. If lengthening the heavy Power Cables, the next size larger (10 gauge) must be used. For the 14 gauge wiring, use the same size or 12 gauge. Always take the time to solder and insulate these connections. Doing it right the first time will save you frustration later!

Ballast Resistors
When using an MSD 5 or Blaster Ignition, if a ballast resistor was originally used in the coil wiring, it should be bypassed. If a ballast resistor was not used, it is not necessary to install one. When an aftermarket coil is used with the Blaster Ignition or MSD 5, follow the coil recommendation for a resistor. A factory ballast resistor does not need to be bypassed with an MSD 6, 7, 8 or10 Ignition.

[DanEC]

I'm beginning to believe that MSD must be an abbreviation for "May Suddenly Destruct" (at any moment). Someone needs to start competing with them and supply a reliable and well engineered ignition system to the aftermarket.

[patrickt]

Originally Posted by davids2toys

If lengthening the smaller wires you can run the same gage or step them up to 12 gage. If lengthening the The POS and NEG heavier wires, no option of keeping the same gage, must be stepped up to 10 gage.
Not being an electrical GURU by any stretch of the imagination, one thing I don't understand is that even if I step up to #10 wire, I will still have the original length of # 12 wire that I will be connecting to. Wouldn't this be a weak link now?

No matter what gauge wire you add to lengthen the existing MSD lines, even if you add wires as fat as your fist, you will still be adding resistance to the line. But fatter wires will add less resistance than skinny wires. The more resistance a line has, the more voltage drop it will have. It's as simple as that.

Regarding mounting the MSD box upside down under the passenger side foot box, so long as you're not driving through a monsoon, I think you'll be alright. I've had it that way for almost a decade... but I've never gotten it wet.