Daze I'm just curious, with that size wire, is it a loss or the battery maintaining its normal voltage. If you have time try this; with the car off measure the battery voltage and the voltage up front. Once again with car off and a small load on (say parking lights) measure the battery voltage and the voltage up front. One maor time with a larger load (Head lights) measure the battery voltage and the voltage up front.This may give you a better feel of the voltage drop or maybe the results will be the same.

Daze wrote:

the battery is in the trunk!!!  I am using heavy duty welding cable to run from the front of the Galaxie to the trunk and it powers the car just fine and starts just fine but when I take a voltage reading at the trunk it only reads 13.5V max.  However if the take the reading under the hood, I get the desired 14.5V.  I wouldn't have thought the cable would have made that much difference but apparently it does.

is your ground wire the same gauge wire as your positive cable? 

Daze wrote:

the battery is in the trunk!!!  I am using heavy duty welding cable to run from the front of the Galaxie to the trunk and it powers the car just fine and starts just fine but when I take a voltage reading at the trunk it only reads 13.5V max.  However if the take the reading under the hood, I get the desired 14.5V.  I wouldn't have thought the cable would have made that much difference but apparently it does.

Fifteen feet of 2 gauge welding cable is not going to create a full volt drop. You have something else going on. You didn't say, but I assume you have the battery grounded to the frame at the trunk area. Based on all the case history I have observed, it is sometimes necessary to run the ground cable back up to the stock location to keep all them little electrons happy. (Yes, 30 feet of 2gauge welding cable costs a lot). You did solder all your connections and cleaned to bright all the fittings?

It is odd that you would have a 1v drop however, 13.5v is enough to charge the battery.  As your biggest current draw is the stater, you may want to check the voltage at the starter with the starter motor engaged.  Recommend disconnecting the ignition so it doesn't start.  As long as the voltage is above 9v, you should be OK.
I'd also recommend, as other posts have, of running a heavy-duty ground cable directly to the engine.  The car body/frame does not make the best electrical conductor.

You are using 00 welding cable!!! Why didn't you tell us you won the lottery!

Hornman wrote:

You are using 00 welding cable!!! Why didn't you tell us you won the lottery!

Didn't win the lottery at the time... this was probably 8 or 9 years ago the price of 00 was not that bad I think I paid less than $1.00 a foot.  I know it is way more than that now.  I am thinking of leaving the battery grounded to the frame and then running a smaller (still heavy gage welding wire) cable as a secondary ground.  The smaller cable would be easier to run and a little easier on the pocket book.  I guess we will see when I go to the welding store to price cable  

BobN wrote:

The un-asked question is where is your alternator picking up the voltage for the voltage sense wire? Should be yellow with a white tracer on the stock connector (labeled A). If you want the battery to have 14.5 volts, that wire would need to be run back to the battery. If you are dumping the alternator under the hood at the old starter solenoid, then that would mean that the alternator would probably be putting out 15V under the hood. To get around this you would have to run the sense and charge wires to the trunk. 14.5 to the battery, and 13.5 to the engine bay.

All things considered, 13.5 is probably fine for keeping your battery charged considering how well the 1G alternator performed that it replaced!

BobN

Aaaaghhh, thats the question I should have asked!!!! The real question to be answered. Whenever I do electrical work the voltage sensing is the key design parameter. Its official, I have CRS!!!

Maybe you having something drawing down the current from your Battery Daze?

Steve69

Daze wrote:

I did a bunch of tests yesterday and I think there are several things going on.  First of all after fully charging the battery I checked voltage with the engine off and no load and there was hardly any voltage drop at the battery compared to under the hood.  As I added a load (engine still off) the difference between under the hood and at the battery increase but was still less than 1V difference.  Then I started the car and repeated the tests I had already done.  At first voltage was good around 14V then as I added a load and it dropped.  At one point it was below 12V then the sound of engine changed slightly and the voltage jumped up to 13.5V.  I bought the alternator used and I am thinking there may be an issue with the regulator.  Another possible issue is improper grounding.  When I had the car running two seasons ago the alternator bracket was bare aluminum.  when I rebuilt the engine I had the bracket powder coated.  Even though my meter says I have good continuity between my alternator and the engine block with no resistance, I am thinking the ground is insufficient.  My plan is to ground the alternator directly to the block and then see if that helps make things more consistent.  I will then look in to running a ground wire from the block all the way to the battery and adding a voltage sensing wire to go from the battery to the alternator.  If all that seams to work than fantastic, but if I am still having issues I will have confirmed it to be the alternator/regulator.  Either way I have a new alt ready to take its place once I work the bugs out and get things set up correctly.

Isn't it normal as a load is placed on the battery for the voltage to drop some, just as long as it doesn't drop too low at idle to the point where its discharging?  You mentioned that the engine sound changed, could that be that the idle went up? which would increase alternator pulley revolutions, which would increase voltage? I'm really not seeing anything wrong here yet.  Do you have underdrive pullies?
 

Just curious about a couple of things.  Are you using the gen light as the "sensing" wire?  If you are, did you plumb a resistor in series with the light so if the bulb goes out the alt will still charge?  

The other thing I was wondering about, is how did you deal with the yellow battery wire at the Galaxie's voltage regulator?   If I remember correctly, there was some wires and the horn relay, that were put on the same junction lug, that needed direct battery voltage.   I will have to pull out my schmatic.  I believe I had to run a wire from the battery to those two wires when I eliminated the voltage regulator.  

correct me if I am wrong here, but the 3g is a 3 wire hookup, no?  One large to the battery, one sensing wire that basically goes to the battery also that "reads" the voltage, and the third wire that goes to the battery charge light.   That wire is what actuates the charge.  If the voltage errrr.  gen light (we are talking Galaxies here, LOL)  bulb fails, the alt will not charge correctly.   That is why the resistor gets put in there.  

What is the battery voltage reading with everything off?   12.6?   If it is, it sounds like its charging, just not aggressively.   I think your problem lies in the excitor wire to the gen light.  


 

Last edited by Greg B (7/13/2013 10:00 PM)

Daze - suggest you look at MAD Electric, good info on 3-wire alternators, Generator-Alternator conversions and voltage sensing ... http://www.madelectrical.com/