View Full Version : Amp guage doesnt move ????


69-ZMAN
May 20th, 00, 03:53 AM
Ive got a problem with the center console amp guage on my 69... it just doesnt want to show any deflection.... does anyone know what the voltage conditions should be on the 2 wires? before i spend the bucks on a new guage I'd like to make sure..... Has anyone ever taken one of these meters apart and fixed anything to make them read better???...

------------------
keepin' it original 69Z

davidpozzi
May 20th, 00, 04:33 PM
I just found this site. It has a good explination of what could go wrong with the other gauges. It won't affect the amp gauge. http://www.fix-a-gauge.com/index.html

------------------
The older I get, the faster I was!

[This message has been edited by davidpozzi (edited 06-07-2000).]

mccorry
May 20th, 00, 07:11 PM
Under normal conditions, I don't believe it should move much. My needle stays on 0 - (middle) unless I have the car off with the lights on, etc....or if the battery is weak and I fire the car up...

Steve

davidpozzi
May 20th, 00, 09:34 PM
Right, My 67 I don't think ever showed more than half way to the first mark. And that was when left sitting with the lights on or cranking a lot.
David

------------------
The older I get, the faster I was!

X77D80
May 20th, 00, 09:52 PM
My 69 Z is a factory guage car and the guage usually sits right in the middle. I'll get movement out of it at idle with the hazards or blinkers on. You can test it by turning the key on (but don't start the car) turn on the hazards. The needle should tick back and forth slightly. If it does, then the guage is probably fine.

glenn396
Jun 7th, 00, 05:10 AM
My '69 factory center console mounted amperage gauge is very active. After cold start, the gauge jumps to 20 amps and continues down to slightly above center (0). Same type of activity when the headlamps are activated.

69-ZMAN
Jun 7th, 00, 06:19 AM
Thanks for the info.... Ive checked out some local cars and have found some that move only slightly to be the norm and a few that move in what I consider to be a readable movement... I still havent been able to find any problem with mine other than ti think the guage itself is not as sensetive as it should be... Ive got a good bud who has a guage that moves considerable maybe we'll try his guage in my car

RacerX
Jun 7th, 00, 10:05 AM
Keep in mind that an ampere gauge measures the amount of current flowing through a circuit; in this case it would measure the amount of current flow through one wire connected to a +12v source. Hence, since the gauge is in series with the wire, if you connect one end of a volt meter to ground and the other to either terminal of the ampere gauge, you should measure +12v (or whatever potential your battery reads.) If you measure from post to post on the ampere gauge, you should read 0v (or very close to it...if you read several volts, then the gauge may be defective.)

Since this wire must carry a substantial amount of current to cause any proportional gauge deflection, be sure that the wire diameter to/from the gauge is sufficiently large (probably 10 gage or so). If so, and you have verified with your freind's ampere gauge that yours is functional, and you read at least 10 volts or so at the gauge, then most likely you have a more complex wiring problem which reduces the current flow through the gauge.



------------------
http://www.geocities.com/dmdirks/Automotive.html

davidpozzi
Jun 7th, 00, 03:47 PM
Zman,
These gauges read "differential voltage" and give you an estimated amp reading.
A normal old fashioned ammeter reads amps by reading voltage drop through a "shunt" It's the brass bar across the back of the gauge. It reads the difference in volts between each side of the shunt and the scale is calibrated in amps.
The Camaro amp gauge reads volts at two points on the car's wiring harness. I assume one near the alternator, the other near the battery. The Camaro's wiring harness is the "shunt" the same as the rear of an ammeter works.
It might be interesting to measure with a digital voltmeter at your ammeter and compare the readings to another car. Perhaps your gauge has a poor connection somewhere. If the other car has good movement with more difference in voltages, then the "problem" is in your cars wiring harness, not the gauge.
I've just learned this stuff myself.
David

------------------
The older I get, the faster I was!