- Thread starter
- #61
I'm going to merge the two "ammeter" threads, and then tell you what happened today. 
Simple midyear question.
- Thread starter 67HEAVEN
- Start date
- Thread starter
- #62
First road test with the replacement "internally-regulated-3-wire-95amp-alternator". I just came back from a blast down the freeway at highway speeds. The round trip was only about 10 miles.
First 5 miles, the ammeter read +20. As I went over the bridge to return home, I glanced at the ammeter again and saw +40 again. It stayed there on the return 5 miles until I shut it down in the garage.
As soon as it cools down a bit, I'm going on a cruise through the neighbourhood to get another reading.
P.S. Thanks to everyone who has contributed to this thread. I'm passing the Tylenol around.
First 5 miles, the ammeter read +20. As I went over the bridge to return home, I glanced at the ammeter again and saw +40 again. It stayed there on the return 5 miles until I shut it down in the garage.
As soon as it cools down a bit, I'm going on a cruise through the neighbourhood to get another reading.
P.S. Thanks to everyone who has contributed to this thread. I'm passing the Tylenol around.
bossvette
Gone but not forgotten
Is there any possibility that your battery is low and is actually still being charged ? The meter was origionally designed to read current flow from a much smaller Alt. maybe the greater charge rate of the 95 amp is confusing the Ammeter like it is everyone else 
KOPBET
Well-known member
Ken Anderson said:
At least one more.
"In real life, the shunt resistor of an ammeter will usually be encased within the protective metal housing of the meter unit, hidden from sight. Note the construction of the ammeter in the following photograph:
This particular ammeter is an automotive unit manufactured by Stewart-Warner. Although the D'Arsonval meter movement itself probably has a full scale rating in the range of milliamps, the meter as a whole has a range of +/- 60 amps."
http://www.allaboutcircuits.com/vol_1/chpt_8/4.html
Note the term D'Arsonval. (he's the galvanometer guy
) In this case, the gavanometer BASED meter movement is used as an ammeter in conjuction with an internal parallel shunt resitance. But the question of whether or not to call the ammeter meter movement a galvanometer is a trivial one anyway. Makes no difference; it isn't relevant to the problem. A rose by any other name ...
- Thread starter
- #65
bossvette said:Is there any possibility that your battery is low and is actually still being charged ? The meter was origionally designed to read current flow from a much smaller Alt. maybe the greater charge rate of the 95 amp is confusing the Ammeter like it is everyone else
I ran a trickle charge to the battery before today's test to make sure it was right up. The 502 fires almost before the starter says, "Howdy".
It likes to run. And, the starter is the new high-torque mini design.- Thread starter
- #66
So, another road test completed, and I noticed a clue. (Right, after all this, hopefully I catch a clue or two :gap )
On firing, the ammeter hit about +35 for half-a-block. Then, it gradually reduced to +20 again. Then, SUDDENLY after about 3 minutes, it banged back up to +40.
"So", says my pea brain. "The car hadn't cooled off completely, and the twin electric fans flipped on. Must be the fans."
Once back in the garage, with the engine shut down, the fans were still operating. I turned the key to ON and noticed only a -05 reading. If the fans caused a spike from +20 to +40 with the engine running, it seems odd for them to only draw -05 with the engine off.
There. I feel better now.
On firing, the ammeter hit about +35 for half-a-block. Then, it gradually reduced to +20 again. Then, SUDDENLY after about 3 minutes, it banged back up to +40.
"So", says my pea brain. "The car hadn't cooled off completely, and the twin electric fans flipped on. Must be the fans."
Once back in the garage, with the engine shut down, the fans were still operating. I turned the key to ON and noticed only a -05 reading. If the fans caused a spike from +20 to +40 with the engine running, it seems odd for them to only draw -05 with the engine off.
There. I feel better now.
B
Billybeau1
Guest
67HEAVEN said:P.S. Thanks to everyone who has contributed to this thread. I'm passing the Tylenol around.
Thanks I needed that.
Do you own an ammeter? If so check what the current is at the battery and compare to the gauge. If its different then your gauge or something in the circuit is probably miswired. If its the same then I still think it might be the battery. At least you've eliminated the alternator. Your getting closer.
KOPBET
Well-known member
Wasted days and wasted nights ....67HEAVEN said:
- Thread starter
- #69
Billybeau1 said:Thanks I needed that.
Yep. I compared the two readings about a hundred pages back. They're identical.
The battery, however, seems happy as a clam.
KOPBET
Well-known member
Remember what they say in real estate: "Location, location, location". With the key on, engine off, all you are measuring with the fans connected to the battery and the location of your ammeter, is current through the alternator (remember the field current?). The current supplied to the fans is coming from the battery, outside of the circuit the ammeter is in (given the way you have the fans hooked up). Have you looked at the specs for the fans to see what the current draw is?67HEAVEN said:
- Thread starter
- #71
KOPBET said:
Okay. So the current through the alternator (fans on / alternator not spinning) is -05 amps. The rest that the fans are drawing could be measured if I could splice a gauge (or meter) between the battery and the fans?
P.S. I'm typing this one-handed. My wife is wrestling with me trying to get the other arm into a straight-jacket. :crazy
KOPBET
Well-known member
67HEAVEN said:
You're catchin' on! And it's -5 because it is coming FROM the battery TO the alternator. A clamp-on meter would save you from a splice. If you insert an ammeter into the circuit make sure it has enough range or you will let the smoke out of it. :W
- Thread starter
- #73
KOPBET said:
Tell me Sensei, where are we headed? Is there a answer somewhere in the Universe? (Trouble is, I'm not sure which question I need an answer for anymore). Should I just drive it until the alternator, the battery, the horns, the fans, or the fuel pump go up in smoke? Maybe it's happy at +40.
KOPBET
Well-known member
Use the "Force" Luke ...67HEAVEN said:Tell me Sensei, where are we headed? Is there a answer somewhere in the Universe? (Trouble is, I'm not sure which question I need an answer for anymore). Should I just drive it until the alternator, the battery, the horns, the fans, or the fuel pump go up in smoke? Maybe it's happy at +40.
The answer is "It depends". If you don't mind the ammeter at +40, leave it be. You are not cooking anything. If you want the thing to measure only charging current, and as such zero out after charge, move the appliances to the main distro point (horn relay bus bar or whatever modded distro point you have), and leave only the charging wire (as is) in the ammeter circuit loop. The thing I would be concerned with is how long those fans run after shutdown, draining the battery. If they auto shut off after a minute or two then you will probably leave it alone. I thunka you are on the right track with the fans. The next step is up to you.
- Thread starter
- #75
Others have suggested moving the "appliances" to the horn relay, so that will be next on my list. What sidetracked me from doing that earlier was the +40 reading I got even after pulling the fuses from the fan and the fuel pump.
I don't think we're in Kansas anymore Toto.
I don't think we're in Kansas anymore Toto.
KOPBET
Well-known member
67HEAVEN said:Others have suggested moving the "appliances" to the horn relay, so that will be next on my list. What sidetracked me from doing that earlier was the +40 reading I got even after pulling the fuses from the fan and the fuel pump.
I don't think we're in Kansas anymore Toto.
How did you drive it without a fuel pump? :confused
- Thread starter
- #77
KOPBET said:
Not very far.
KOPBET
Well-known member
67HEAVEN said:
I thought maybe you had Fuelie riding shotgun with a squeeze box.
(faster!, Fuelie, faster!) - Thread starter
- #79
KOPBET said:I though maybe you had Fuelie riding shotgun with a squeeze box.
I tried to talk Z28Canuck into lying on the roof with a jar of high-test and a hose, but he wouldn't go for it. :eyerole
67HEAVEN said:
gee, I wonder why not........... :eyerole
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