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another frustrating alternator problem

3K views 13 replies 4 participants last post by  T-bucket23 
#1 ·
Guys, I need your help. I have a Painless Wiring kit installed on my 67 Camaro with a 100amp 1-wire alternator. There is a MAXI 50amp fuse installed between the charging positive alternator wire/post and battery. I also have a ford starter solenoid for my mini-starter.

Here is the setup: ignition key (ON) - diode - remote starter solenoid (purple wire) - starter wire + battery positive - MAXI fuse - Alternator positive

For past couple months, my alternator stopped charging. No 14.4Volts, battery dieing, I had to jump start my car the other day. To remedy this, I replaced the alternator's rectifier/regulator and trio diode with new ones from Kragen ($40 in parts). The car worked great for a day - 14.38 volts. Yesterday I had the same problem - 12.2 volts at the battery and the alternator. There is no voltage between the negative battery post and the alternator mounting bolt (no drains according to my alt. instructions). All grounds for the engine, firewall etc are new. There is no resistance on the alternator wire. I also have a voltmeter gauge inside. I read multiple posts on the board about bumping the rpms to 1500, putting some load on the alternator (lights, amps, sound system). It doesn't help, I had lights on, 2 amps goings with a sub, 2k, 3k rpms, the voltmeter was still showing 11.9V, the alternator didn't kick in.

I bought an alternator kit from MAD and would like to go to Napa and buy their 12Si 89amp alternator, 3-wire. Then install an idiot light with a diode for troubleshooting. I am taking my present alternator to Napa as well to have them check it out.

Any other tests I can run to troubleshoot the problem?

A few questions:
1. Can I install a 12Volt computer LED in the dash as an idiot light?
2. I have a Powermaster starter, did I do the right thing by jumping B and S terminals on it. I have only one 2-gauge wire going to it. I also ran a direct grounding wire from the negative battery post to the starter body. Should I ditch it (I had a lot of hot start problems with headers before)?
3. When MAD instructions refer to the ignition key (ON), does it means ACC (turn the key to the right and and it stays there), or when I crank the engine?
4. Should I get a one-wire alternator instead from Napa? That 100amp I have is a chrome nice-looking unit. However, finding replacement parts for it wasn't easy.
5. Can a messed-up diode in my ignition circuit prevent the alternator from charging the battery?

Thanks for your help,
Denis
'67 Camaro RS
 
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#2 ·
The diode will block current flow in one direction. Current (amps) is flowing from the battery but not back to it to charge it. Remove the diode. You don't need it. Why did you install it?

If you have #10 wire connected to the 100 amp alternator, the 50 amp MAXI fuse could be increased to 80 amp.

The Ford solenoid is redundant. You don't need it unless you want it for theft prevention by controlling it from a separate button.

The idiot light circuit is an output of the alternator. You need to get an alternator with this feature.

You can use an LED but for an idiot light but a "loading" resistor will be required in parallel with the LED to mimic load of a standard idiot light.

The B terminal on the starter is for the battery main wire. The S terminal is for the start wire from ignition switch. If you jumper them the starter will operate continuously. The only reason to jumper these terminal is to jump start the engine or to bump the engine.

The #2 wire is OK if it's less than 3 feet long. If the battery is in the trunk, I use at least 1/0 for the positive and negative cables direct to the starter.

vicrod
 
#3 ·
Thanks for the reply, Vicrod.

I used a diode since Painless wiring kit diagram showed it in the ignition circuit.
Ford solenoid acts as a remote starter solenoid to avoid the hot start problems due to the headers. Instead of one 16-gauge purple wire going directly to the starter (the headers melted it before), I run it to the fender mounted solenoid, and from there a 2-gauge wire to the starter positive.

What capacity loading resistor do I need in series with the LED light? How many ohms?

Thanks,
Denis
 
#4 ·
What alternator are you using?
A (1) wire or a (1) wire with ignition, idiot light terminals.

The diode is used only in the ignition wire (Painless wire #914) to prevent feedback into the ignition circuit when you shut the ignition off.

I think I understand what you doing with the Ford solenoid. You will need the jumper on the starter between B and S.
The wires to the alternator and fuse block must be connected on the battery side of the solenoid.

The LED requires a (ballast) resistor in series to limit current. I would purchase an LED already setup for 12 volts such as those sold by Speedway Motors. They provide a nice package with a lens, ballast resistor and push-in mounting.
Install it, if it won't go out and the system is charging, you may need a Parallel resistor (not series) to load the circuit. A 50 ohm, 5 watt resistor should work.



vicrod
 
#5 ·
Doc here, :pimp:

Question, Is the "remote" solenoid set up so as to shut the power off to the cable going forward and starter main power after the engine is started?

And is The Alternator hooked up here...?

If so..the Alternator may be shutting down when the solenoid cuts power to the starter..and cable going forward..

Measure at the point of connection to be sure, you should have 12 volts there 24/7..If it is dead, you will have to move the Alternator wire to the battery post Itself, or a "Hot At all times" terminal..

That Diode is provided to prevent Ignition run on..It needs to be installed in the Ignition power , not inline with the Alternator..and it may also be open..remove it, make a solid connection there and test it again..If you get run on, you may have to Isolate the Ignition line power.

Measure your diode with an ohm meter, RX1, Calibrated 000, and it should only read in one direction, If it reads in both, or neither, It's bad, so If you need it on the Ignition get another. If you have a later model Ignition switch , you may not even need a diode.

Doc :pimp:
 
#6 ·
Dont over look the fact that one of the new parts may have failed. The cheapy parts at the low end stores usualy have a very high mortality rate. You said it worked for a day after you repaired it so I would think your general wiring setup is ok. Did you charge the battery after the first failure. A dead battery will eat an alternator. Did you test the old parts to see which were bad. The diode trio is the most common. There is a way to test the regulator live. I forget exactly what the procedure is but it involves instrting a small scre driver into a whole in the alt case and grounding a tab to the case. Maybe someone here can shed some more light on the procedure.
 
#7 · (Edited)
Thanks, guys, for your help.

I bought a 89amp 12SI alternator, traced my brown cable from fuse box in the engine bay labeled 'voltage generator'. I am using a Painless Wiring kit for 67 Camaro.

Installed the diode to the post 1 on the alternator, then to the brown wire. Post 2 went to the ford solenoid where all my hot wires are, including the battery.

Started the car, the alternator works great giving 14.5V in the beginning, then the voltage went down to 14V (battery is one week old). Turned the stereo on, sub, amp and headlights. Nice constant 14V.

A little problem - my instrument cluster has 2 blinker indicators ON at all times when I turn the headlights on. They are somewhat dim, when flashing they get brighter. I don't remember that happening before. Did I loose a ground somewhere by accident? Or is this normal for this Camaro year?

Is that brown wire correct one to use as a voltage 'turn-on'?
Is it normal when the ignition switch is in the ACC position, I get the GEN light on?

Thanks!!!
Denis
'67 Camaro RS
 
#8 ·
darom said:
Thanks, guys, for your help.

I bought a 89amp 12SI alternator, traced my brown cable from fuse box in the engine bay labeled 'voltage generator'. I am using a Painless Wiring kit for 67 Camaro.

Installed the diode to the post 1 on the alternator, then to the brown wire. Post 2 went to the ford solenoid where all my hot wires are, including the battery.

Started the car, the alternator works great giving 14.5V in the beginning, then the voltage went down to 14V (battery is one week old). Turned the stereo on, sub, amp and headlights. Nice constant 14V.

A little problem - my instrument cluster has 2 blinker indicators ON at all times when I turn the headlights on. They are somewhat dim, when flashing they get brighter. I don't remember that happening before. Did I loose a ground somewhere by accident? Or is this normal for this Camaro year?

Is that brown wire correct one to use as a voltage 'turn-on'?
Is it normal when the ignition switch is in the ACC position, I get the GEN light on?

Thanks!!!
Denis
'67 Camaro RS
Doc here, :pimp:

So the last alternator turned out to be defective as T Bucket Said (nice call T.. :thumbup: ) ? or not? sounds like it ..

On your lights you may have cross wired your flasher Indicator lights into the instrument panel dimming line..turn the Dim up and down..that will tell you the story..

Doc :pimp:
 
#9 ·
Yes, it looks like the other alternator was junk. What I don't understand is why it would fail with new trio diode and rectifier/regulator?

Doc, what about the GEN light in the ACC position. Is it supposed to be ON? How can I check if the light works - unhook post 1 on the alternator?

Thanks!
 
#10 · (Edited)
Doc here, :pimp:

The Windings may have been failing OR did you replace the brushes? That would kill it also..And as was said..New stuff Isn't exactly the answer to the problem..

Electrical parts have high out of the box fail rates now a days..always have them , If possible (Modules, and the like) Tested Before you leave the store..


I'm not sure on the Painless kit If the GEN light works in both positions or not...

The Stock did NOT..

However, some like it (and chimes) to run in ACC, so you don't forget and leave the key in the ignition AND in ACC..flatting the battery or losing your rod..Painless may be setup this way for that reason..you need to refer to the painlesss wire diagram for that..

It won't hurt a thing (if you don't run ACC for days) to leave it that way.

To verify all that (the IGN switched side of the buss) Is on the right side of the switch, turn the key to ACC and measure the voltage at the coil..It should be dead. If it has power your ACC and Switched Buss's may be reversed.you'll have to change them.

Doc :pimp:
 
#11 ·
I put my gauge cluster back in, now I don't get any strange blinker lights any more :) It autofixed itself. Everything runs great, I am getting now 14.4V with the lights and stereo on.

Excuse my electrical noobiness, Doc, but where exactly at the coil do I need to measure? ACC position, alternator post 1 and ground with a voltmeter?

Thanks again for your input! T-bucket - nice catch on the failed parts.

Denis
'67 Camaro RS

PS I took my chrome alternator with old internals to AutoZone, all test failed (regulator, diode). I am glad I didn't beat the dead horse.
 
#12 ·
Doc here, :pimp:

Naw, Even more simple than that..

Just turn it to ACC and go to the coil + (if external coil) or The BATT wire (if HEI) If you read 6 to 12 volts it may be on both (or wrong ) Buss..

Those autofixes are great huh? You probably needed a good ground..and got it putting the cluster back in.

Doc :pimp:
 
#14 ·
darom said:
Yes, it looks like the other alternator was junk. What I don't understand is why it would fail with new trio diode and rectifier/regulator?

Doc, what about the GEN light in the ACC position. Is it supposed to be ON? How can I check if the light works - unhook post 1 on the alternator?

Thanks!
Most of the Autozone and other cheapo parts store electrical parts are very marginal at best. I have seen them fail alot. The other issue is if your battery was real low, you can burn up the alternator in real short fashion. There are also a lot of connections internal to those GM alternators that go bad and need to be re-soldered.

Glad I could help
 
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