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  #21  
Old 04-04-2016, 12:43 PM
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Rogan Rogan is offline
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Not stupid, as sometimes I overlook simple stuff, but I did check it.

Sent using Sprint's invisible microwaves..
Remember that this issue is intermittent.

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SOLD: 01 2500 qcsb 4x4 HO 6spd, 2" level, 5" exh., Edge Juice, bhaf, 16mpg
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  #22  
Old 04-04-2016, 02:41 PM
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OK, you have a good ground from the alternator field wire? Have you checked the battery temperature sensor wires? Do you have any voltage coming from the PCM to excite the alternator?
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  #23  
Old 04-04-2016, 03:03 PM
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Do the gauges still flicker/act up? Have you checked the wiring from the key switch down the steering column for a possible break in a wire? What happens if you wiggle the key when it is running?
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  #24  
Old 04-08-2016, 06:50 AM
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Quote:
Originally Posted by MnTom View Post
OK, you have a good ground from the alternator field wire? Have you checked the battery temperature sensor wires? Do you have any voltage coming from the PCM to excite the alternator?
None from the PCM.

Quote:
Originally Posted by MnTom View Post
Do the gauges still flicker/act up? Have you checked the wiring from the key switch down the steering column for a possible break in a wire? What happens if you wiggle the key when it is running?
Nope.. no anomalies with wiring breaks that I can find.
I added an external voltage regulator 2 days ago.. It charges fine, but on the high side (14.8-15.2) which will cause the CEL to come on and off every once in awhile. Good ground from EVR to Alternator.. I can't seem to figure out why I have such high voltage, though..
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SOLD: 96 2500 sclb 4x4, 5spd swap, cam, stack, #10, bhaf, 16.5*, 27mpg
SOLD: 01 2500 qcsb 4x4 HO 6spd, 2" level, 5" exh., Edge Juice, bhaf, 16mpg
SOLD: 97 3500 cc-drw, built 47re, 3 disk, 4" exh., #100, bhaf, gauges
SOLD: 02 QCSB 2500 4x4 5.9-auto
SOLD: 97 ECLB 2500 4x4 V10-auto.. junk..
CURRENT:'06 2500 ThunderRoad QCSB 5.9CTD 4x4, built Auto; '02 Silverado 2500HD 6.0L CrewCab LB 4x4; '14 vw cc r-line 2.0t 6 speed

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  #25  
Old 04-08-2016, 08:51 AM
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Here is some interesting reading, long, but good reading:
Quote:
Originally Posted by randysrepairshop.com (no longer available)
Normally, you must measure 13.75 to 14.75 volts at the battery terminals while the engine is running. Less than 13.75 volts and the battery will not charge fully. Over 14.75 and you will start to boil the water out of the battery. Older GM batteries can tolerate a little higher voltage, and 15.2 or 15.4 volts is usually not catastrophic with most batteries.

Your charging system, as with most Chrysler systems, is extremely simple and reliable once you understand how it works. There is one thing they did though to complicate it, but there is a solution. You saw two small terminals on the back of the alternator. They are attached to the two brushes on the two ends of the spinning coil of wire, (the rotor). A previous poster is correct; they are interchangeable. However, the two wires going to those terminals go through a black plastic block. There's no easy way to be sure which wire goes to which terminal. Those two wires are definitely different and can not be mixed up.

On older cars that came with the external regulator you are trying to use, one wire was blue and one was green, and they were clipped onto the alternator separately. Either wire could be attached to either terminal.

The first thing you need to check is the voltages on the two small alternator terminals. One must have 12 volts, (actually full battery voltage). It will appear for only two seconds after turning on the ignition switch, then it will be there constantly when the engine is running. The voltage comes from the Automatic Shutdown (ASD) relay which also sends current to the injectors, coils, fuel pump or pump relay, and O2 sensor heaters. If the engine runs, the relay circuit is working. If the 12 volts is missing on one of the small alternator terminals, there has to be a break in the wire between the splice and the alternator. That's not common.

You'll get the most diagnostic information from the voltage reading on the second small alternator terminal. If it's very near zero, the brushes inside the alternator are worn. On a lot of vehicles they can be replaced without removing the alternator from the engine. The wire can also be grounded, (shorted to ground). That will result in zero volts on that terminal too, however the alternator would charge wide open.

If the system is working properly, the voltage on the second terminal will be less than battery voltage and more then zero, typically 4 - 11 volts. The lower the voltage, (which means the larger the difference or DROP across the two terminals), the larger the electromagnet, and the more output current leaving the alternator. If you find battery voltage on one terminal and less than battery voltage on the other terminal, yet the output current or voltage are too low, suspect an open diode in the alternator's output circuit. It will still work and may appear to test ok on a test bench, but it won't be able to pump as much maximum current as normal. Most off-the-car testers only test for output or lack of output, not specifically how much output because at maximum output, it takes more horsepower to run the alternators than the tester's motors can produce.

The third possibility is you will find full battery voltage on both small alternator terminals. This indicates an open circuit (break) in the wire going to the regulator, or the regulator is open. No current will flow, so no voltage will be dropped across the rotor. Think of a garden hose. If you step on the hose, the pressure (voltage) drops at the nozzle and the water dribbles onto your shoe! If you turn the nozzle off, you will build full water pressure at the nozzle even though you're still standing on the hose. Voltage in a wire works the same way.

You suspect your voltage regulator is open. That would stop current from flowing through the rotor, there would be no electromagnet, and no induced output voltage. If you are correct, you will measure the exact same voltage on both small alternator terminals. Grounding the proper terminal on the alternator will make it charge wide-open momentarily to prove the alternator and rest of the circuit is working. The problem is figuring out which terminal to ground. On older cars, it was always the green wire. On your truck, you can't easily tell which terminal to ground because the wires are both green and they go through that black plastic block. On my web site, I describe a trick to figure out which terminal is which, but that's more info. than you need here to fix your truck. You can ground this green wire at the engine computer too to do the same thing. Grounding it there includes the wire in the circuit, so you're testing it too right away. If grounding the wire right at the computer makes the alternator charge wide-open, the only possibilities left are an open regulator in the computer, or a spread terminal in the connector. The regulator is the most likely cause. That's a fast way of verifying ALL the rest of the circuit is capable of working correctly.

The whole charging circuit is one long series circuit; power source to alternator, alternator to regulator, regulator to ground. What you are trying to do is to remove the regulator in the computer and insert a different regulator not in the computer. Your regulator in the computer also uses one of the 12 volt supply wires to measure system voltage and one of the ground wires to compare the voltage to. Your new external regulator does exactly the same thing. The 12 volt feed wire powers the regulator's circuitry and is where it measures system voltage; the ground is the regulator's case that has to be bolted to a clean shiny spot on the body sheet metal.

In the picture you posted, there's a note on top that says the two wires to the alternator can be switched. That's only true if the black plastic block with the attached wires is removed. Then you can run wires all over the place. This is where you are making things way too complicated. If you have that block off now, with the engine running, find which one of those two terminals in the block has the full battery voltage. Put the block back on the alternator, then attached another wire on that terminal and run it to the one marked "12 volt from battery" on your picture. It will turn off anytime the engine is not rotating so it won't kill the battery. It's doing exactly the same thing you want to do with another relay, except it's much more effective. Add a second wire to the other small alternator terminal and run it to the second regulator terminal. Ground the regulator, and you're done. It can be even easier to cut the green wire at the engine computer and just pull it over to the regulator and attach it instead of running a new wire.

These external regulators have temperature compensation built in just like your original unit in the computer. Charging a battery is a chemical reaction. Chemical reactions occur more slowly in cold temperatures, so to help the battery charge in cold weather, they raise the desired charging voltage a little. That's where it can be acceptable to find a little more than 14.75 volts across the battery terminals. The other thing to be aware of is the engine computer monitors operation of the voltage regulator. When it fails to see the current flow through the regulator, it assumes there is no current flow through the field winding, (rotor), and therefore no output from the alternator. This will result in low voltage to the injectors, coil(s), and fuel pump. Although the truck might run fine for a long time, these things can cause a change in tail pipe emissions that the engine computer can't control. That is cause to turn on the "Check Engine" light on the dash. While driving it this way won't hurt anything, if a different, unrelated problem occurs that would result in the light turning on, you will never know because the light is already on. The typical diagnostic fault code that will be in the engine computer's memory would be "Field current not switching properly". The computer can't monitor the external regulator so it will just be up to you to watch the dash gauge and headlights for symptoms. These external regulators are also very reliable. Most lasted the life of the car. 99 percent of junkyard units will be fine too but watch out for rust on the case that could interfere with a good ground.

The last thing you will lose is modification of charging system voltage based on outside circumstances. Full output from a 100 amp alternator can easily draw ten horsepower from the engine. That ten horsepower might be just what you need to complete the pass in time or make it up a steep hill while pulling a trailer. At wide-open-throttle, the computer will command the regulator to turn the alternator off for a short time so that ten horsepower is available for other stuff. Some cars will bump up the charging voltage a little when the rear defroster is turned on. If the engine is running hotter than normal, such as when stuck in traffic, the engine computer might lower the charging voltage to reduce the load on the engine. Everything the engine computer knows can be used when making decisions on selecting the desired charging system voltage. None of that was really necessary years ago when cars were much simpler and more reliable before they added all the computers to them.
I have been reading that you may have a poor ground somewhere between the battery and regulator and also that there have been a lot of aftermarket regulators that just don't seem to be up to the task.
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5 timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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  #26  
Old 04-08-2016, 09:03 AM
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Rogan Rogan is offline
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good info, thank you.
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SOLD: 96 2500 sclb 4x4, 5spd swap, cam, stack, #10, bhaf, 16.5*, 27mpg
SOLD: 01 2500 qcsb 4x4 HO 6spd, 2" level, 5" exh., Edge Juice, bhaf, 16mpg
SOLD: 97 3500 cc-drw, built 47re, 3 disk, 4" exh., #100, bhaf, gauges
SOLD: 02 QCSB 2500 4x4 5.9-auto
SOLD: 97 ECLB 2500 4x4 V10-auto.. junk..
CURRENT:'06 2500 ThunderRoad QCSB 5.9CTD 4x4, built Auto; '02 Silverado 2500HD 6.0L CrewCab LB 4x4; '14 vw cc r-line 2.0t 6 speed

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  #27  
Old 04-09-2016, 09:14 AM
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anoldbiker anoldbiker is offline
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Tom, are you thinking of
http://randysrepairshop.net/index.html
.. but trying the .com address instead ?
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  #28  
Old 04-09-2016, 10:37 AM
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MnTom MnTom is offline
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Originally Posted by anoldbiker View Post
Tom, are you thinking of
http://randysrepairshop.net/index.html
.. but trying the .com address instead ?
I don't know for certain, but it sure looks like that is what it should be. The link is what was in the quoted part that I copied and pasted (other that the not working part).
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5 timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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