Amp gauge question
Thread Starter
Drifting
Joined: Aug 2010
Posts: 1,880
Likes: 4
From: Montgomery Texas
Amp gauge question
When it have my turn signal on my amp gauge moves in sync with my blinker. Also at night when I have the AC on and the lights my gauge reads below half way when at idle. my alternator is a new high amp alternator with a low idle kick on. Is this a common thing that I should not worry about?
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
The electronics tech in me says it's a short. I'm guessing that since you didn't mention it, the light isn't blinking too fast. It should cycle on then off about once a second. The blinkers and fog lights in C4s seem to be a pain to me, but you can pull it off without too much trouble. Use your repair manual to see how to get to this stuff.
A few questions. Does it happen with both blinkers, or just one of them? Does it happen with the emergency lights?
A few questions. Does it happen with both blinkers, or just one of them? Does it happen with the emergency lights?
Thread Starter
Drifting
Joined: Aug 2010
Posts: 1,880
Likes: 4
From: Montgomery Texas
The electronics tech in me says it's a short. I'm guessing that since you didn't mention it, the light isn't blinking too fast. It should cycle on then off about once a second. The blinkers and fog lights in C4s seem to be a pain to me, but you can pull it off without too much trouble. Use your repair manual to see how to get to this stuff.
A few questions. Does it happen with both blinkers, or just one of them? Does it happen with the emergency lights?
A few questions. Does it happen with both blinkers, or just one of them? Does it happen with the emergency lights?
Everything works just fine, both blinkers do the same thing. I am not use to seeing the amp gauge move on a vehicle when the turn signal is turned on. This could be normal on a 1990 corvette i just dont know.
I know for a fact that my Alternator is good I just put it on the car and I had it built for me. I have these alts built for my boat and they are high amp, single wire, low idle kick on with the best parts.
Could a weak battery be the cause of this? I know if I leave the car door open for say 1 hour the battery will be DEAD.
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
The battery could definitely be the issue. If you have one that you KNOW is good, I would try it out though before you go buy a new one.
If that doesn't work, then you definitely have some sort of short in your system. They are a pain to hunt down, but if you have a wiring diagram, it makes it easier. I'll try to find one, but if you have one, I can tell you where to look. All you have to do is find one point where both the left and right side blinkers are at the same point. Find where the light bulb itself is and work your way through both sides until they come together. Trace from all 4 bulbs, but you only need to find a link between the two sides. It'll probably be a relay. They go bad sometimes and without warning. Shorts wreak havoc on our ships and they are a headache. So, if the battery doesn't fix it, then your are in for a long haul of tracing. It shouldn't cause much damage to your car, if at all, so take your time.
If that doesn't work, then you definitely have some sort of short in your system. They are a pain to hunt down, but if you have a wiring diagram, it makes it easier. I'll try to find one, but if you have one, I can tell you where to look. All you have to do is find one point where both the left and right side blinkers are at the same point. Find where the light bulb itself is and work your way through both sides until they come together. Trace from all 4 bulbs, but you only need to find a link between the two sides. It'll probably be a relay. They go bad sometimes and without warning. Shorts wreak havoc on our ships and they are a headache. So, if the battery doesn't fix it, then your are in for a long haul of tracing. It shouldn't cause much damage to your car, if at all, so take your time.
Instructor
Joined: Jun 2008
Posts: 173
Likes: 0
From: Norman OK
Did you have these symptoms before the alternator change?
Every charging system test in the FSM warns to start with a fully charged battery to provide proper voltage and amps... A failing or internally shorting battery could drive the voltage regulator crazy.. A battery going dead in 1 hour of interior light operation sure indicates it's weak. Have the battery load tested.
Also, instead of a short somewhere out in the vehicle, I would look more toward high resistance. A short should blow a fuse. A good project is to access and clean the multiple grounds. As this is a 90, it may be time.....
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Did you have these symptoms before the alternator change?
Every charging system test in the FSM warns to start with a fully charged battery to provide proper voltage and amps... A failing or internally shorting battery could drive the voltage regulator crazy.. A battery going dead in 1 hour of interior light operation sure indicates it's weak. Have the battery load tested.
Also, instead of a short somewhere out in the vehicle, I would look more toward high resistance. A short should blow a fuse. A good project is to access and clean the multiple grounds. As this is a 90, it may be time.....
As the motor idles the alt is barely able to keep up with the demand since there is no reserve amperage from the battery...so its actually running off the alt and that will wear on the voltage regulator...the low speed-high draw.The HEI ignition system takes LOTS of voltage...and will drain a good battery in 10-15 minutes running the engine with NO accessories running. Low voltage also causes misfireing from the HEI and poor performance when battery voltage is low or unstable.
Get the battery load tested, and what I did was get an Optima...it has about 50% more cold cranking amps (hi-hi reserve amperage) than any other quality brand and will power everything easily. Its a funny thing...it takes several days for this big battery to reach its max charge because its capacity is so large but that is in your favor, as its equally as hard to drain it. This is a heavy sucker, and it barely fits, but it will go in and bolt up. Bring around $200+ but it will end the low voltage issues.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
I noticed your car is a 90. I am going to assume you are correct it is an amp gauge and not a volt gauge. I cannot not recall the different gauges per year. So assuming it is infact an amp gauge it shoud infact twitch with the turn singles, drop when you create other loads. There are a lot of veribles to how much Battery condition, wires, alt ect. all efect that. But movement is normal. It is picking up the amps being drawn from the system.
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Thread Starter
Drifting
Joined: Aug 2010
Posts: 1,880
Likes: 4
From: Montgomery Texas
As the motor idles the alt is barely able to keep up with the demand since there is no reserve amperage from the battery...so its actually running off the alt and that will wear on the voltage regulator...the low speed-high draw.The HEI ignition system takes LOTS of voltage...and will drain a good battery in 10-15 minutes running the engine with NO accessories running. Low voltage also causes misfireing from the HEI and poor performance when battery voltage is low or unstable.
Get the battery load tested, and what I did was get an Optima...it has about 50% more cold cranking amps (hi-hi reserve amperage) than any other quality brand and will power everything easily. Its a funny thing...it takes several days for this big battery to reach its max charge because its capacity is so large but that is in your favor, as its equally as hard to drain it. This is a heavy sucker, and it barely fits, but it will go in and bolt up. Bring around $200+ but it will end the low voltage issues.
I have two Blue top Optima in my boat and I have had then for over 5 years with no problems. I love the Optima Batteries and I will be replacing my Battery as soon as I get a chance.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Everything works just fine, both blinkers do the same thing. I am not use to seeing the amp gauge move on a vehicle when the turn signal is turned on. This could be normal on a 1990 corvette i just dont know.
I know for a fact that my Alternator is good I just put it on the car and I had it built for me. I have these alts built for my boat and they are high amp, single wire, low idle kick on with the best parts.
Could a weak battery be the cause of this?
I know if I leave the car door open for say 1 hour the battery will be DEAD.
I know for a fact that my Alternator is good I just put it on the car and I had it built for me. I have these alts built for my boat and they are high amp, single wire, low idle kick on with the best parts.
Could a weak battery be the cause of this?
I know if I leave the car door open for say 1 hour the battery will be DEAD.
The output of the alternator at idle is low due to the lower RPM. I have seen that effect on lots of cars when the blinker is going. At a long stop light on my 94, I can watch the volt meter drop, but not a great deal
If at 1000 - 1500 RPM you are charging 14.0-14.7 volts, that would be a normal condition. A short would pop a fuse or a system might not be working. Does not sound like you have those symptoms.
If your battery is 2 - 4 years old in a hot climate it might need to be replaced.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
As the motor idles the alt is barely able to keep up with the demand since there is no reserve amperage from the battery...so its actually running off the alt and that will wear on the voltage regulator...the low speed-high draw.The HEI ignition system takes LOTS of voltage...and will drain a good battery in 10-15 minutes running the engine with NO accessories running. Low voltage also causes misfireing from the HEI and poor performance when battery voltage is low or unstable.
Get the battery load tested, and what I did was get an Optima...it has about 50% more cold cranking amps (hi-hi reserve amperage) than any other quality brand and will power everything easily. Its a funny thing...it takes several days for this big battery to reach its max charge because its capacity is so large but that is in your favor, as its equally as hard to drain it. This is a heavy sucker, and it barely fits, but it will go in and bolt up. Bring around $200+ but it will end the low voltage issues.
Your voltmeter dips in sync with your turn signals with the engine idling because your alternator cannot put out enough current to keep its output voltage constant at idle rpm. It won't hurt a thing so don't worry about it unless your idle rpm is below 700 rpm which is where it is supposed to be.
