New to here - fixed a problem but have another

[7539]

Recently bought a 64 IV which has had a lot of work already done to it. Basically a small oil leak and some body work and then a paint...had the problem of it not starting when warmed up - changed the coil as the forum said and it fixed the problem like a dream. Friend of mine pulled the Weber carb and cleaned it all up...everything is much better. However, I have a couple of small problems and one big one.

I have a couple of dash switches that don't work, maybe because I have a headlight missing and the wiring may need going over. The panel lights and heater fan don't work...minor issues I feel sure.

My problem is the generator. Car is positive earth and generator is negative, which should be no problem. But try as I might I can't get it polarized and make it work. Is there a decent way to check it? I don't seem to be getting voltage to it, which maybe is the voltage regulator? It had basically killed the old battery. I replaced it after a couple of weeks of starting it off of a trickle charger but I will have to fix the problem before long or it will ruin the new one.

I see that most people just change over to an alternator which I assume is a fairly straight-forward process, except for the bracket fabrication.

Which direction do you guys and gals suggest I go next?

Thanks to you all - as a new owner, this forum has been gold for me. These cars are the greatest - very underestimated - I love to drive mine and get lots of comments and waves, even though it looks pretty bad on the outside...Thanks again

 

[jumpinjan]

If you want to upgrade to an alternator, I recommend to buy "new". Like this one
http://www.ebay.com/itm/MG-MGB-TRIU...Parts_Accessories&hash=item2ea87dd14a&vxp=mtr
No bracket mods; You need to fabricate a cable assembly and need to find the right size pulley. I found the GM style pulleys are about right.
It will take some doing to get it right, but they work great.
I wrote up an article on how to do it in the old club newsletters.
Jan

 

[Tom H]

You say the car is Pos earth , but the generator is Neg. How do you know the gen is Neg? How did it get that way?

Jan's suggestion is a good one, but I and others have installed a Hitachi 14231, See post #5 here for more details:
http://www.sunbeamalpine.org/forum/showthread.php?t=21022

Regarding the bracket, you should be able to obtain a standard SV bracket from someone on this forum. The bracket may or may not need mods to the holes that mount it to the block. No pulley changes needed with the 14231

Tom,

 

[jumpinjan]

The Lucas alternator needs the series V bottom mount, like Tom said. The top mount could be from an MGB, I think.
I was thinking about making these top brackets because a good one could be hard to find.
The wire connection is made up with two wires, and you follow the series V wiring schematic. I'm not sure of the Series IV charging circuit.
Jan

 

[7539]

sorry I'm slow

I was on vacation for a few days. The generator is marked negative ground is how I know it was at one time a negative fround generator. This should be a non-issue due to re-polarizing the generator.

That being said, the alternator route seems to be most correct, if one can decide on which to use.

I am wondering though if I am getting power to the generator. When checking with a meter, it doesn't seem apparent that I am. I am thinking that a change in voltage regulator would be the next step...

comments?

 

[Tom H]

Hello 75,

It's been years since I last worked on a Generator charging system, so I am not 100% sure, but I don't think there should be any battery voltage at the generator when just sitting and not running, You say " I am wondering though if I am getting power to the generator. When checking with a meter, it doesn't seem apparent that I am." You understand, I assume, that the generator "powers" the battery, not vice versa. I think the "voltage regulator" disconnects the battery from the generator until the generator is putting out enough voltage to charge the battery. otherwise the generator would drain the battery when parked. So, until the generator is running and working and putting out voltage there is no connection between the battery and the generator.

I suggest you follow the step by step procedure in the WSM to isolate whether you have a generator or regulator problem.

Tom

 

[7539]

Recently bought a 64 IV which has had a lot of work already done to it. Basically a small oil leak and some body work and then a paint...had the problem of it not starting when warmed up - changed the coil as the forum said and it fixed the problem like a dream. Friend of mine pulled the Weber carb and cleaned it all up...everything is much better. However, I have a couple of small problems and one big one.

I have a couple of dash switches that don't work, maybe because I have a headlight missing and the wiring may need going over. The panel lights and heater fan don't work...minor issues I feel sure.

My problem is the generator. Car is positive earth and generator is negative, which should be no problem. But try as I might I can't get it polarized and make it work. Is there a decent way to check it? I don't seem to be getting voltage to it, which maybe is the voltage regulator? It had basically killed the old battery. I replaced it after a couple of weeks of starting it off of a trickle charger but I will have to fix the problem before long or it will ruin the new one.

I see that most people just change over to an alternator which I assume is a fairly straight-forward process, except for the bracket fabrication.

Which direction do you guys and gals suggest I go next?

Thanks to you all - as a new owner, this forum has been gold for me. These cars are the greatest - very underestimated - I love to drive mine and get lots of comments and waves, even though it looks pretty bad on the outside...Thanks again

Thanks Tom...will do

 

[7539]

one more question

when you replace the generator on a negative ground car, the single wire system goes from the alternator to the positive post on the battery or the negative? Is that a stupid question? haha thanks

 

[RootesRacer]

Hello 75,

It's been years since I last worked on a Generator charging system, so I am not 100% sure, but I don't think there should be any battery voltage at the generator when just sitting and not running
Tom

This is true, the generator "dynamo" output or "D" terminal is isolated from the battery by a mechanical rectifier in the control unit (cut out contact).
The "Field" or "F" terminal however should be getting near battery voltage to it when the generator not turning (or dynamo output is below 14 or so volts).

The regulator module does 3 things more or less.
1) It disconnects the generator output from discharging into the generator when the voltage of the generator is lower than the battery voltage.
2) It modulates the field current with a contact switch in an attempt to regulate the dynamo output voltage to what the battery wants (at that temperature).
3) It limits the field current in the event that the dynamo current exceeds generator capacity.

The first 2 of 3 of these things are adjustable mechanically, but you have to know what the hell you are doing else REALLY mess these things up.

If you at least have a voltmeter, you may be able to diagnose the problem.

As for "polarizing" the generator, thats simple to do.
You disconnect the "F" terminal from the regulator or at the generator and jumper the battery output (+ or - depending on if neg or pos ground) and connect it briefly to the "F" terminal of generator or wire 4 or 5 times.

Doesnt matter if you want pos or neg ground, only matters that you set the battery up correctly for how you want to run first.

The generator doesnt care if its used neg or pos ground, the field coil needs to be biased so the control loop is not extremely hysteretic as it regulates.
Left on its own (without polarizing) the field coil would eventually bias itself and work fine.


Another thing to mention is changing over from pos to neg ground, you really also want to change your coil though in the short term it will work fine.

HTH

 

[7539]

This is true, the generator "dynamo" output or "D" terminal is isolated from the battery by a mechanical rectifier in the control unit (cut out contact).
The "Field" or "F" terminal however should be getting near battery voltage to it when the generator not turning (or dynamo output is below 14 or so volts).

The regulator module does 3 things more or less.
1) It disconnects the generator output from discharging into the generator when the voltage of the generator is lower than the battery voltage.
2) It modulates the field current with a contact switch in an attempt to regulate the dynamo output voltage to what the battery wants (at that temperature).
3) It limits the field current in the event that the dynamo current exceeds generator capacity.

The first 2 of 3 of these things are adjustable mechanically, but you have to know what the hell you are doing else REALLY mess these things up.

If you at least have a voltmeter, you may be able to diagnose the problem.

As for "polarizing" the generator, thats simple to do.
You disconnect the "F" terminal from the regulator or at the generator and jumper the battery output (+ or - depending on if neg or pos ground) and connect it briefly to the "F" terminal of generator or wire 4 or 5 times.

Doesnt matter if you want pos or neg ground, only matters that you set the battery up correctly for how you want to run first.

The generator doesnt care if its used neg or pos ground, the field coil needs to be biased so the control loop is not extremely hysteretic as it regulates.
Left on its own (without polarizing) the field coil would eventually bias itself and work fine.


Another thing to mention is changing over from pos to neg ground, you really also want to change your coil though in the short term it will work fine.

HTH

Thanks again for the info...I have learned more from reading it than I ever thought possible!

 

[Tom H]

7539 said:

when you replace the generator on a negative ground car, the single wire system goes from the alternator to the positive post on the battery or the negative?

Assuming the alt is made for a Neg gnd car, as almost all are, yes, connect the output from the alternator to the battery side of the solenoid , or to the ammeter (if installed).

Most alternators have an additional wire that goes to the ign warning lamp. (The other side of the warning lamp still goes to the ign sw) . This warning lamp circuit gives you an "idiot light" indication when the Alt is not working, but also provides better low RPM operation on some alternators.

There may also be a third wire that is used to sense the voltage so the alt can maintain the proper voltage at the point where this extra wire is attached. Normally you connect this wire somewhere in the white circuit, either at the white wire terminal at the fuse holder or at the ignition switch. With this wire added, the Built n regulator in the ALt will maintain the correct (typically 14.5 V) voltage at the white wire. Without it, there will be 14.5 V at the Alt output terminal, but a little less V in the white circuit because of the V drop in the main lead due to heavy current flowing thru that power lead.

Tom

 

[7539]

alternator

Tom or everybody: without reading through the volumes of opinions on alternators, what is the most common one to use? is it the 14231 or the other one - 7121 W or something...one can use the current bracket with less modification and no pulley change...thanks in advance...

 

[Tom H]

If you do a search on this forum for 14231, you will find 30 threads, If you search on AC10, you will find 5 threads.

Either conversion requires the SV alternator bracket to replace the SIV Generator bracket. The 14231 includes a pulley. In my installation of the 14231 I had to modify the bracket to move the Alt fwd a bit. But most others have had no need to do so. I concluded that I had an oddball bracket.

You can buy a 14231 from your local parts place, typically under $75 for a rebuild one.

Tom

 

[7539]

If you do a search on this forum for 14231, you will find 30 threads, If you search on AC10, you will find 5 threads.

Either conversion requires the SV alternator bracket to replace the SIV Generator bracket. The 14231 includes a pulley. In my installation of the 14231 I had to modify the bracket to move the Alt fwd a bit. But most others have had no need to do so. I concluded that I had an oddball bracket.

You can buy a 14231 from your local parts place, typically under $75 for a rebuild one.

Tom

Thanks again Tom. So I need a series V bracket to begin...that was the part that I missed in reading all of those threads that I needed pointed out to me..

 

[Tom H]

And that is the main mounting bracket. You also need the adjusting bracket, and that is slightly different than even the standard SV one. In my case I installed the 14231 to replace my original SV Alt and for the adjuster I just used the original, but bolted on an extension made from some other junker, just a slotted piece of steel. See attached pic for what my adjuster bracket looks like

The wiring changes are not difficult, but it helps to have some understanding of auto wiring.

Tom

 

[DanR]

I used a single wire Delco Alternator on my '67 SV with the original alternator bracket. Fit perfect as I recall. Then I found an adjustment rod from a ford that worked fine after a small bend was put in it for better alignment.

 

[7539]

I used a single wire Delco Alternator on my '67 SV with the original alternator bracket. Fit perfect as I recall. Then I found an adjustment rod from a ford that worked fine after a small bend was put in it for better alignment.

Thanks for the help!

 

[7539]

A Quick Question

Hey guys and Tom:

I converted to an alternator today - I have two questions:

We changed from positive to negative ground.

1. How do I convert the Tach from positive to negative?
2. Do I have to make changes at the coil?

I think everything else is OK...so far...

Thanks!

 

[DanR]

Tach ?

Get in touch with Tom H (Hayden)

He did two tach's for me. They are nicely done.

 

[7539]

I found online a way to reverese the tach and that the wires on the coil have to be switched; however, she won't start, although she turns over great...still problem solving