Alternator / Voltage Regulator

[davids2toys]

Originally Posted by patrickt

I added up my amperage loads on my car. With every single switch I have turned on I'm still only in the 40's. The only way I can test that circuit breaker would be to bench test it or short it out... so I'll just leave it be.

Maybe I'm way off here, but couldn't you use that clamp meter to measure your Real/actual amperage going thru the CB?

[patrickt]

Originally Posted by davids2toys

Maybe I'm way off here, but couldn't you use that clamp meter to measure your Real/actual amperage going thru the CB?

Yes, with the engine off and everything turned on that would give an exact reading on the total amperage. It was just easier to add it all up in my head than to walk downstairs to the garage and actually measure it. Since all my lights are LEDs, which account for very little current, my fans and head lights are pretty much it. Of more interest is the amp draw by the fans. If you look at your SPAL data sheet, it has a nice little table that shows the different current draws based on the temperature and whether you have it as a pusher or puller. When I shut down my engine, and it is nice and hot, the current draw, as measured, is five amps or so more than when the engine is cool. Of course, the voltage is a little lower too since the alternator is not running.

[davids2toys]

Originally Posted by patrickt

Yes, with the engine off and everything turned on that would give an exact reading on the total amperage. It was just easier to add it all up in my head than to walk downstairs to the garage and actually measure it. Since all my lights are LEDs, which account for very little current, my fans and head lights are pretty much it. Of more interest is the amp draw by the fans. If you look at your SPAL data sheet, it has a nice little table that shows the different current draws based on the temperature and whether you have it as a pusher or puller. When I shut down my engine, and it is nice and hot, the current draw, as measured, is five amps or so more than when the engine is cool. Of course, the voltage is a little lower too since the alternator is not running.

I borrowed a friend's amp tool See post #45 Bad Starter
Car OFF and cold, with the fan, high beams, and wipers on I got about 15 amps going thru the CB. Seems pretty good to me?
No brake lights, horn or blinkers.
I might have to do this again. It is after midnight and I'm beat. Maybe I screwed this up...LOL

[patrickt]

Originally Posted by davids2toys

Maybe I screwed this up...LOL

You did. There's no way that's only pulling 15 amps. If you take your headlights alone, two 60 watt bulbs is 120 watts, divide that by 12.6 volts, and you get 9.5 amps for the lights alone. I'll look at your other post on "Bad Starter" to see if I can see what you're doing wrong.

[davids2toys]

Originally Posted by patrickt

You did. There's no way that's only pulling 15 amps. If you take your headlights alone, two 60 watt bulbs is 120 watts, divide that by 12.6 volts, and you get 9.5 amps for the lights alone. I'll look at your other post on "Bad Starter" to see if I can see what you're doing wrong.

You're right, it was either the gauge or me. I went out and re-did it this morning and it was not 15, it was 5 amps. when I saw that, I tried it on the 10 amp scale and it gave me about 2 amps. I canned the whole idea with this gauge. I went to Sears today and bought the clamp gauge you suggested. I will try again Friday or Sat. I am just putting the probe on both sides of the CB. Speaking of the CB, I got the new one today(type 3). What a cheap looking piece of crap compared to the metal auto resetting Type 1 that is in the car now. Last week I tested the resistance in the old CB and it read zero or .01ohms, I forgot. I will do the same to this new one and see what I get.
Just went out and checked it. It flashes a number for a split second and goes to 0.000 immediately. The number looks to be .750 most of the time before it flashes to zero. When I say split second I mean it. does this sound right?
In testing the CB I just went from stud to stud and disconnected no wires. . I guess my thinking was I just wanted to see what was running thru the breaker. Maybe that is why the very low reading. Please enlighten me on the Patrick procedure correct way to do this test...LOL
Dave

[patrickt]

Originally Posted by davids2toys

In testing the CB I just went from stud to stud and disconnected no wires. I guess my thinking was I just wanted to see what was running thru the breaker. Maybe that is why the very low reading. Please enlighten me on the Patrick procedure correct way to do this test...LOL
Dave

Naaah, you're wasting your time doing it that way -- and you're only going to fool yourself with the results. Measuring resistance will only get you so far. For example, let's say you have two wires, one is a nice new fat 0 gauge battery cable and the other is a ratty old piece of copper strand the thickness of a dog hair. You get out your trusty multimeter and you check the resistance on both wires and they both show just about no resistance. Maybe the dog hair is actually a little less in ohms, who knows. What does the test tell you? Nothing. The moment you put a load on the dog hair the wire will go *poof* and you'll have an open circuit. In order to really measure a "thing" that is on an automotive circuit, be it a span of wire, a circuit breaker, a fuse, a connection, etc., you must perform a "voltage drop test." That's your next lesson after you master clamping your inductive amp meter around a wire.

[davids2toys]

Originally Posted by patrickt

Naaah, you're wasting your time doing it that way -- and you're only going to fool yourself with the results. Measuring resistance will only get you so far. For example, let's say you have two wires, one is a nice new fat 0 gauge battery cable and the other is a ratty old piece of copper strand the thickness of a dog hair. You get out your trusty multimeter and you check the resistance on both wires and they both show just about no resistance. Maybe the dog hair is actually a little less in ohms, who knows. What does the test tell you? Nothing. The moment you put a load on the dog hair the wire will go *poof* and you'll have an open circuit. In order to really measure a "thing" that is on an automotive circuit, be it a span of wire, a circuit breaker, a fuse, a connection, etc., you must perform a "voltage drop test." That's your next lesson after you master clamping your inductive amp meter around a wire.

I wasn't measuring resistance, I was trying to measure amps going thru it