Team Chevelle banner
1 - 20 of 20 Posts

·
Registered
Joined
·
848 Posts
Discussion Starter · #1 ·
I don't know whats up with my ammeter in my 65. Its a stock gauge car. I never see any movement. I took a voltmeter and tested the power coming out of the connector. I got like 11 on wire and 12 on the other wire. So thats a +- of 1 volt. So it should be moving right? After that test, I was though no big dealt the guage is busted. I tried different gauge and still nothing. I tried to test both of these guages. I just took a fresh 9v battery and touched both tof the leads. Both of the guages moved all the way to Charge and Discharge. Now im getting really confused. I try both of the guages with the connector connected both way. I turned on everything possible and still no movement (Wipers,Headlights, Blower on High speed). Whats up with it? I find it hard to believe that with all those things on its on pulling any amps. I am lost :(
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #3 ·
can you elaborate on that, so do you mean when the car is running?
 

·
Registered
Joined
·
1,555 Posts
With the car running, turn on the headlights, radio, heater blower and dome light...see if the ammeter moves then. Then, turn the engine off. The ammeter SHOULD move into the "discharge" or - side.
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #5 ·
if only i could figure out why the radio won't turn on :(
 

·
Premium Member
Joined
·
6,740 Posts
Originally posted by Adman:
if only i could figure out why the radio won't turn on :(
Well that's another matter. As far as checking the ammeter it's not important. Jerry was suggesting you turn everything on to generate a large current draw. Radio doesn't draw much anyway. Turn your bright lights on, along with the, heater, dome light.
Power to the radio? Fuse?
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #7 ·
I turned the car to ACC and turned all of those things on, and no movement.

As for the radio, Its got plenty of power, a good ground. But i think theres a short somewhere. I unplugged all the speakers and amp, the only that is plugged in now is power, coming off the old clock lead i think, memory wire going to the fuese block (bat), and grounded. Im gonna try a new ground, but thats all I can think off. I figured its a short because i'd hit the wiring harness and it would cut out or something like that, but I don't really know how test for shorts, so i just started to unplug stuff
 

·
Registered
Joined
·
1,555 Posts
IF your ammeter is installed correctly, just turning on your headlights without the engine running SHOULD show some deflection toward the - (minus)side of the scale. Turning on "bright beams" will cause an even larger current draw and a larger deflection. If there is no movement at all, there is a good chance that the meter is wired incorrectly. The meter should be in "series" with the 12 volt supply to the entire vehicle (except the large starter solenoid connection).
 

·
Premium Member
Joined
·
2,221 Posts
Sorry guys- The factory amp gauge is not wired in series and doesn't get full current flow. It is actually a volt meter scaled in amps, it measures the voltage drop across the main power wire between the horn relay and the J-block.

If you can access the back of the amp gauge connect the volt meter leads to the two terminals of the gauge. Turn on the headlights, the volt meter should measure a small voltage. If you have a VOM with a mili-volt -mV- range select it. .4 to .5 volts or 400 to 500 mV will be full scale on your amp gauge. With your head lights on bright and heat/AC blower on you will likely read less than 200 mV. or .2 volts. A typical digital VOM with a mV scale can only measure a max of 200 mV you should be below that.

If your volt meter does measure a voltage I would suspect a problem with the gauge. If no voltage is measured it indicates a problem with the wiring, probably one of the two leads is open. I believe 65 didn't use fusible links like later Chevells, I think 67 was the first year to get them.
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #10 ·
It was working before, but what promprted this little adventure, is that i had just installed a new heater core, and i was just letting the car idle about about 30 minutes, and it just died, flat out dead battery. It was the battery, and the alternator is charging, But never any movment on the amp guage. I guess im just gonna rewire the amp guage myself. See what confuses me the most is, that I have current Voltage, and since I have voltage I have to amps flowing through the circut, but why isn't the guage measuring any flow.

I guess i'll just rewire it myself tomarrow. So one lead to the junction block and one wire to the the horn relay? 10 guage wire or what?

Elree, your correct, there are no fusible links, they aren't in the diagrams.
 

·
Premium Member
Joined
·
6,740 Posts
Originally posted by Adman:
See what confuses me the most is, that I have current Voltage, and since I have voltage I have to amps flowing through the circut, but why isn't the guage measuring any flow.
Just a note, current and voltage are 2 different things. You can have voltage, potential, pressure, without current, depends on resistance. You cannot have current flow without voltage though. Measure voltage across a battery that is not connected to anything. You measure voltage but there can be no current because there is not a complete path between + and -. My point is this, don't assume that because you read voltage at any point in a circuit that it is a complete circuit or that you have current flow. Think of voltage as water pressure, the potential to move water. The amount of water flow is like current flow. If all your faucets are closed you have pressure but no flow. You have to open a faucet, reduce resistance, complete the circuit, in order to have flow.
 

·
Registered
Joined
·
235 Posts
65 chevelle uses a shunt across the guage. nothing should be connected to the guage but the wires , one to horn realay, other to connector behind batery. the heavy wire between the bat across the radiator and the horn realy is the shunt.
 

·
Premium Member
Joined
·
2,173 Posts
Didn't I just see Elree say that the gauge in a 65 is actually a volt meter measuring voltage drop, not an ammeter? That makes a BIG difference. Is everything else electrical stock? I sense from the statements regarding radio and an amplifier (I'd just hit the harness and it would work) there's more potentially wrong here. Sounds like some wires have been butchered, connections not made well (obviously not soldered) etc. etc.. I think Elree hit nail on the head. A volt meter that isn't bridging the load isn't going to measure any drop. I'm suspecting bad wiring.
 

·
Registered
Joined
·
7,758 Posts
Originally posted by Finally:
</font><blockquote>quote:</font><hr />Originally posted by Herb:
Didn't I see Elree say that the gauge in a 65 is actually a volt meter measuring voltage drop, not an ammeter?
That's what he said. </font>[/QUOTE]Except if the shunt opens. Wasn't the best design.
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #19 ·
About the Radio, I checked all the connections. Redid one that goes to the fuseblock and the memory lead. What seemed to be the problem at first, was I was pulling main power off of the old radio power, or even the clock I think, but the orignal connector was bad and would not make a connection every once and a while, So i just cut It off and buttspliced it to the main power lead. I changed my ground to a better spot behind the dash. I click the power on, CD changers comes on, just no radio. (the cd changer get power through the radio)

But the worst part is that This is a custom autosound system. If you ever think of ordering their stuff, don't!!! I've had to have the deck repaired 2 times, 2 new wiring harnesses, and the CD changer itself repaired 2 times, all of this is in 1 year!
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #20 ·
Wired the ammeter up and now it works fine. I didn't feel like dealing with searching for the wire under the fender etc.

I also returned my custom autosound stuff today, so i get $500 to blow on my new stearo. Im getting new pioneer stuff. Deck in the glove box, and cd changer in the trunk again.
 
1 - 20 of 20 Posts
Top