Battery draw issue

[NewAge1970]

the plug in cannot be plugged in backwards, and no its an externally regulated alt, it has a tag that says so. so if i take my volt meter and put them on the leads in the plug in on the alt, it will show voltage one way, but not the other. is that what youre saying?

[NewAge1970]

VetteVette, i believe mine looks that way, but i dont remember off hand, its been a few days since i have been under the hood of my truck. but the alternative is a plug in on the side instead of the back, so i believe that is the same as my alternator. this issue is killing me because even if i put a new flex plate in i cant drive it reliably.

[NewAge1970]

Originally Posted by domeier

You said you have a two-wire alternator, but it's hooked up to an external regulator? Are you sure it's not internally regulated? Not sure if that would cause your draw... but here's a diagram anyway: Good luck.

Im 100% positive that it is externally regulated. ive had two different types of regulators, one was the expensive digital one, and one was the cheaper old school one that you have to "charge up". so i have no idea.

[domeier]

If I were you, I'd do this:

1) Take that first color schematic that vettevette posted and trace out the alternator/bat/reg wiring to make sure it's right. You can see by the diagram that the alt bat pole will always be hot. Someone with an external voltage reg should pipe up here and tell you what the field and sensing wires should show with key off.

2) Start troubleshooting by isolating the draw from the battery out: With the key off, look for a spark, (or use a test lamp) when you touch the + bat cable to + bat post.

3) Disconnect the accessory wire from the + bat cable, and check for the spark. If it still sparks, the problem is in your starter circuit. If not, it's down the line from the accessory connection.

4) Accessory goes to the bat connection on the alt. Disconnect at the alt and check for the spark at the battery. Follow the juice patch on the schematic, and disconnect circuits until you isolate it.

5) Oh, and see if you have voltage coming off the alt ground. It's not impossible to get a bad alternator from the parts store.

6) Chin up, old boy! Pip pip, and all that!

[NewAge1970]

Originally Posted by domeier

If I were you, I'd do this:

1) Take that first color schematic that vettevette posted and trace out the alternator/bat/reg wiring to make sure it's right. You can see by the diagram that the alt bat pole will always be hot. Someone with an external voltage reg should pipe up here and tell you what the field and sensing wires should show with key off.

2) Start troubleshooting by isolating the draw from the battery out: With the key off, look for a spark, (or use a test lamp) when you touch the + bat cable to + bat post.

3) Disconnect the accessory wire from the + bat cable, and check for the spark. If it still sparks, the problem is in your starter circuit. If not, it's down the line from the accessory connection.

4) Accessory goes to the bat connection on the alt. Disconnect at the alt and check for the spark at the battery. Follow the juice patch on the schematic, and disconnect circuits until you isolate it.

5) Oh, and see if you have voltage coming off the alt ground. It's not impossible to get a bad alternator from the parts store.

6) Chin up, old boy! Pip pip, and all that!

haha thanks for the advice, im good with the mechanical part, just not the electrical part. as most of you all guessed im a 17 year old kid with his own project. i got the truck from my grandpa last year and there are so many things gone wrong. the truck was well taken care of, but ive got my own ideas for everything else. my grandpa was going to keep it original for the most part. but the motor wasnt orig, neither was the trans. so i got the idea in my head to make it a street rod to race all the other stupid highschool kids in my town with their mommys and daddys diesel trucks. i paid my dues for my truck to show them up. another problem i have too is that i joined the Marine corps, i leave in june. i dont have much time to get it finished and fixed to give back to my grandpa for the time being. so any help is appreciated!

[VetteVet]

Originally Posted by NewAge1970

the plug in cannot be plugged in backwards, and no its an externally regulated alt, it has a tag that says so. so if i take my volt meter and put them on the leads in the plug in on the alt, it will show voltage one way, but not the other. is that what youre saying?

I didn't mean that the plug was backwards HA HA, I meant that some one may have inserted the wires backwards. They might be in the wrong terminals on the VR also. You should have power on the blue wire that goes to the F at all times and the the white wire to R will only have power when the key is on.

To check the alternator internal diodes you need to set the multi-meter on the Ohms scale for resistance. and place one meter lead on the R terminal and the other lead on the alternator body and watch for a reading. If you get nothing then swap the meter leads and watch for the reading. You should get something one way but not the other. If you get readings both ways then you have a blown diode and current will leak from the battery to the ground and drain the battery.

Now do the same thing on the F terminal and the large post on the back of the alternator. You must disconnect all the wires going to the alternator when you do this.

If you take the alternator back to the store and it checks bad maybe you can get them to give you a good deal on a 12 SI internally regulated model and we can convert it for you.

Props to you for joining the Marines, I doubt that you will ever regret it. It may not be exactly like the recruiter described but if you work hard and apply yourself it can be very rewarding. In this economy it is a very good way for young people to earn a living and to continue their education.

[NewAge1970]

Thanks vette, how do you convert it ? It's the second car quest alternator .
Posted via Mobile Device

[VetteVet]

You will need to get an adapter for the alternator plug or just cut one off a junker and splice the white wire to the no 1 terminal wire in the plug and splice the blue wire to the no.2 wire terminal in the plug.

Then pull the voltage regulator plug off and jumper the brown and white wires together and the red and blue wires together. That should do it. You can then remove the voltage regulator and put it on the shelf or sell it to a restorer.

Consult the diagram below for reference.

[fixit-p]

I agree with vettevet if the alternators test bad go for the upgrade, it's simple and you wont regret it. But here is some info on the externally regulated alt.

Here is a diagram of the 10DN alt.



The F (field) terminal has a direct path to ground through the field winding's so any power applied there with the engine off will drain the battery.

The R (stator) terminal has no path to ground except for through the battery terminal or if the rectifier bridge was bad.

Here's another diagram which also shows the regulator. You have to be real specific in telling us which wires have power for anyone to be able to help.



Troubleshooting sequence.

Disconnect 2 wire plug at alternator (leave batt. wire connected) and test for power at both the R&F terminals on the alt. Power present at either terminal= bad alt

Test the white wire on the plug for power with key off, if power is present=bad reg. (Applies to mechanical reg as shown above, solid state may be different (no schematic) but if the alt checks out this shouldn't drain the battery because there is no path to ground on the R terminal again except for through the battery terminal or if the rectifier bridge was bad).

Test the blue wire on the plug for power with key off, if power is present disconnect reg plug and test brown wire for power if no power at brown wire = bad reg, if power is present at brown wire check your ignition circuit.

[stellar]

OK, on an external regulated alt the white and blue should have no power with the key off when testing at the alt plug.

On an internal the F will be hot all the time and the R will be hot with the key on.

Since this is an external reg type alt You should have no volts to the blue wire when the key is off. If you do you will be supplying current to the rotor causing a draw. You may even feel the alt become warm when the key is off if this the case. The white R terminal will be dead until the alt begins to charge, and will show a volt reading around 8 volts.

With the key off the only hot wires will be the alt post and one wire at the reg.

[NewAge1970]

That's what I thought stellar, does this mean my ignition switch is bad?
Posted via Mobile Device

[oldgold70c10]

Originally Posted by NewAge1970

That's what I thought stellar, does this mean my ignition switch is bad?
Posted via Mobile Device

Do your wipers, radio, or heater fan come on when the ignition switch is in the off position? These are all powered by the same switch contact as the wire that excites the rotor, the accessory circuit. If the answer is yes, it is the ignition switch.

[NewAge1970]

Originally Posted by oldgold70c10

Do your wipers, radio, or heater fan come on when the ignition switch is in the off position? These are all powered by the same switch contact as the wire that excites the rotor, the accessory circuit. If the answer is yes, it is the ignition switch.

No, that's not the case
Posted via Mobile Device

[oldgold70c10]

If the blue wire in the alternator plug is hot then, back up to the regulator. Unplug the 4-prong plug going to the regulator. The brown wire (terminal 4) is the one that's fed from the accessory circuit. Check it. It could be crossing with another wire that is hot at all times somewhere in the harness. If it is dead when the key is off, there is a problem in the regulator. Use the ohms scale and check between the F and 3 terminals on the regulator. It should be open. If it is, there are problems in the wiring, if it is not open, get another regulator.

[NewAge1970]

Open as in? And if I have a wire crossed, I'm screwed
Posted via Mobile Device

[oldgold70c10]

Originally Posted by NewAge1970

Open as in? And if I have a wire crossed, I'm screwed
Posted via Mobile Device

Should read infinity, OL, etc. Not connected.

As for the crossed wire, disconnect the battery, unplug the regulator & ohm between the brown & red wire wires in the regulator plug. With the key off, it should read open.

But back up first and check the regulator.

[72lb4x4]

I'd go back to square one, and try to figure out what's happening. Restate the symptoms very simply.

If the starter doesn't turn the engine after sitting, what's the voltage on the battery when:

both cables are connected;
one of the batt cables is disconnected;
when the starter is turning.

If you put a charger on the battery for 2 days with one battery cable disconnected, what's the voltage on the battery in the above 3 tests after charging?

Let the battery sit overnight after charging as above with cable disconnected. Reconnect the cable. Does it spin the engine as expected?

New parts are often crap so saying X has been replaced often just means another potentially bad part has been added to the mix.

The test light in series is a good test. What have you found from doing that?

We can't read your mind, or see what's happening, so you need to give us info on what's happening.

[oldgold70c10]

Originally Posted by 72lb4x4

I'd go back to square one, and try to figure out what's happening. Restate the symptoms very simply.

If the starter doesn't turn the engine after sitting, what's the voltage on the battery when:

both cables are connected;
one of the batt cables is disconnected;
when the starter is turning.

If you put a charger on the battery for 2 days with one battery cable disconnected, what's the voltage on the battery in the above 3 tests after charging?

Let the battery sit overnight after charging as above with cable disconnected. Reconnect the cable. Does it spin the engine as expected?

New parts are often crap so saying X has been replaced often just means another potentially bad part has been added to the mix.

The test light in series is a good test. What have you found from doing that?

We can't read your mind, or see what's happening, so you need to give us info on what's happening.

That is a very good idea.

A great first place to look for key off drains if you don't have a working horn is the horn relay. Unplug it. If it clicks when you unplug it, you found your key-off drain. (or at least 1)

[VetteVet]

Originally Posted by stellar

OK, on an external regulated alt the white and blue should have no power with the key off when testing at the alt plug.

On an internal the F will be hot all the time and the R will be hot with the key on.

Since this is an external reg type alt You should have no volts to the blue wire when the key is off. If you do you will be supplying current to the rotor causing a draw. You may even feel the alt become warm when the key is off if this the case. The white R terminal will be dead until the alt begins to charge, and will show a volt reading around 8 volts.

With the key off the only hot wires will be the alt post and one wire at the reg.

I noticed this and saw that I had said that the blue wire should be hot at all times and realized that, that was not true with the external regulator until the key was on and the regulator points were closed. This connects the red wire on no3 of the external regulator with the F terminal blue wire.

Thanks to fixit-p for the schematic he posted. VV

[VetteVet]

Originally Posted by NewAge1970

Well, I have no idea where the draw would be, I know that if I un plug my alternator, my draw goes away.
Posted via Mobile Device

This is what set everybody on the alternator regulator path.

[NewAge1970]

Thanks guys for all of the help, its currently ****ty weather outside so I'm not going to test or a little bit. i will get back to you.
Posted via Mobile Device

[NewAge1970]

Originally Posted by oldgold70c10

That is a very good idea.

A great first place to look for key off drains if you don't have a working horn is the horn relay. Unplug it. If it clicks when you unplug it, you found your key-off drain. (or at least 1)

Okay, this sounds plausible. Although my horn is disconnected from the horn itself and the button on the steering wheel. It's an aftermarket gt steering wheel. But where is the relay for sure.
Posted via Mobile Device

[NewAge1970]

Going by fixit-ps troubleshooting. I have a bad alt. The regulator plug, the brown wire has NO power. The alternator plug in spades, the r and f terminals have NO power And the blue wire HAS power with the regulator plugged in
Posted via Mobile Device

[oldgold70c10]

If the blue wire has power with the regulator plugged in and the alternator unplugged, its a bad regulator. Your check of the two terminals on the alternator where the plug goes shows the alternator is good. Get another regulator. That blue wire is supplying power to the field when it shouldn't, causing your drain.

As for the horn relay, it is under the dash on the firewall above and to the left of the steering column. It has 3 wires: green, black, and red.

[NewAge1970]

One more question, on the new regulator, it's got a male spade off of the number four terminal, what is it for?
Posted via Mobile Device