1997 1998 charging problems
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
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From: ottawa ontario
1997 1998 charging problems
Anyone here have charging problem s with their 1997-98 vette..Voltage in the car says 13.0-13.2. Put a volt meter on the alternator and it says 14.4 while the battery says 13.7 while idling with a vot meter on it..goes down to 12.7 and high as 13.7 while driving. Load test on battery came back ok and the alternator light in the car is off..Any ideas???? I checked for loose wires and bad grounds now there..
I did convert my car from a 6 speed to an auto..R the 6 speed and auto alternators the same?
I did convert my car from a 6 speed to an auto..R the 6 speed and auto alternators the same?
Last edited by mitymikec; Jun 5, 2007 at 06:59 PM.
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
Voltages look about normal for C5 although I have not owned a 97/98. If you are concerned about voltage I’d look into C6 alternator as they consistently seem to run about a volt higher then C5.
Mike
Mike
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
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From: ottawa ontario
This is what i did today..I went out and bought a new 1000CCA battery today..Checked and the grounds, took them all off and cleaned them before i re installed them..I did the one under the battery on the frame rail..Also did the tow that are on the frame rails beside the head lights..Still the same thing.When i start the car cold it's at 14.0 them when it heats up it starts dropping..As i drive it comes down to low 13s then occasionally bounces into the high 12's quickly them back upto the low 13s..I have a small amp but nothing big..Once i turn on the tunes and lights the voltage drops to the high 12s again..
Does anyone know if there is suppossed to be a grounding strap on the alternator? There is nothing there now..Looks like mounting bracket is the only ground for the alternator..I measures the voltage at the alternator when its running with a volt meter its 14.4 and 14.2 at the battery when the car is running..
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Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
What you have described is par for the course… or it’s normal. On startup voltage will always jump up a bit because battery is charging, then after some time voltage will stabilize.
Now I had some problems on my past 04 so I paid attention to voltages and charging portion. With that said your car seems fine and operating normally. The discrepancy between your multimeter readings and displayed voltage is normal and that’s why Racetronix sells a hot wire harness for fuel pump. You will always see a voltage drop from alternator post to fuse box or relay output.
Today on my C6 post startup voltage was 14.9 but stabilized at 14.0 after some time, again normal and subtract about 1 volt for C5.
If you want a higher voltage output maybe look at Caspers as they have a nice module that will bump voltage up when at WOT. I’ve used the module and it works.
Mike
Now I had some problems on my past 04 so I paid attention to voltages and charging portion. With that said your car seems fine and operating normally. The discrepancy between your multimeter readings and displayed voltage is normal and that’s why Racetronix sells a hot wire harness for fuel pump. You will always see a voltage drop from alternator post to fuse box or relay output.
Today on my C6 post startup voltage was 14.9 but stabilized at 14.0 after some time, again normal and subtract about 1 volt for C5.
If you want a higher voltage output maybe look at Caspers as they have a nice module that will bump voltage up when at WOT. I’ve used the module and it works.
Mike
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
What you have described is par for the course… or it’s normal. On startup voltage will always jump up a bit because battery is charging, then after some time voltage will stabilize.
Now I had some problems on my past 04 so I paid attention to voltages and charging portion. With that said your car seems fine and operating normally. The discrepancy between your multimeter readings and displayed voltage is normal and that’s why Racetronix sells a hot wire harness for fuel pump. You will always see a voltage drop from alternator post to fuse box or relay output.
Today on my C6 post startup voltage was 14.9 but stabilized at 14.0 after some time, again normal and subtract about 1 volt for C5.
If you want a higher voltage output maybe look at Caspers as they have a nice module that will bump voltage up when at WOT. I’ve used the module and it works.
Mike
Now I had some problems on my past 04 so I paid attention to voltages and charging portion. With that said your car seems fine and operating normally. The discrepancy between your multimeter readings and displayed voltage is normal and that’s why Racetronix sells a hot wire harness for fuel pump. You will always see a voltage drop from alternator post to fuse box or relay output.
Today on my C6 post startup voltage was 14.9 but stabilized at 14.0 after some time, again normal and subtract about 1 volt for C5.
If you want a higher voltage output maybe look at Caspers as they have a nice module that will bump voltage up when at WOT. I’ve used the module and it works.
Mike
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
Ok so here is where i am now..I put a 120 amp load on the car today and the alternator was charging to 12.2 volts..I am guessing that means the alternator and battery are all good..So now what? I think i will start to probe the PCM grounds and see what is up down there..
Any other ideas?
Any other ideas?
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
I don’t understand your concern, what problems are you having? I did the Casper module as a test to see how far fuel system can be extended without boost-a-pump. Ask the PTK turbo guys what there voltages are (they are much lower then yours).
Go to Speed Inc site and purchase module if you are that concerned, I personally saw ~14.6 volts at WOT (on DIC). I can’t tell you how much of a change it was but fuel pump(s) and coil packs benefited from higher voltage. Note I had inline booster fuel pump with a semi-return type system.
Oh when racing you turn as many loads off as possible so you should not see 120 amps and voltage should/will be higher.
If I still had module I’d send it up to you. Casper’s is local to me so I just picked it up and I got a good deal.
Mike
Go to Speed Inc site and purchase module if you are that concerned, I personally saw ~14.6 volts at WOT (on DIC). I can’t tell you how much of a change it was but fuel pump(s) and coil packs benefited from higher voltage. Note I had inline booster fuel pump with a semi-return type system.
Oh when racing you turn as many loads off as possible so you should not see 120 amps and voltage should/will be higher.
If I still had module I’d send it up to you. Casper’s is local to me so I just picked it up and I got a good deal.
Mike
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
I don’t understand your concern, what problems are you having? I did the Casper module as a test to see how far fuel system can be extended without boost-a-pump. Ask the PTK turbo guys what there voltages are (they are much lower then yours).
Go to Speed Inc site and purchase module if you are that concerned, I personally saw ~14.6 volts at WOT (on DIC). I can’t tell you how much of a change it was but fuel pump(s) and coil packs benefited from higher voltage. Note I had inline booster fuel pump with a semi-return type system.
Oh when racing you turn as many loads off as possible so you should not see 120 amps and voltage should/will be higher.
If I still had module I’d send it up to you. Casper’s is local to me so I just picked it up and I got a good deal.
Mike
Go to Speed Inc site and purchase module if you are that concerned, I personally saw ~14.6 volts at WOT (on DIC). I can’t tell you how much of a change it was but fuel pump(s) and coil packs benefited from higher voltage. Note I had inline booster fuel pump with a semi-return type system.
Oh when racing you turn as many loads off as possible so you should not see 120 amps and voltage should/will be higher.
If I still had module I’d send it up to you. Casper’s is local to me so I just picked it up and I got a good deal.
Mike
I want as much voltage at the pump as possible for better fuel delivery....thanks for the input..
Former Vendor
Joined: Feb 2004
Posts: 10,876
Likes: 8
From: Las Vegas NV
St. Jude Donor '06 & '12
If its running in the high 12's, low 13's during normal driving (not at night) then there is definately something wrong.
You might try and increase the size of your ground straps on the driver and passenger side.
Its a quick test:
Take (2) 8 guage wires and temporarily run each one of them from the side of the block to the stud on the frame. If it corrects the problem, then just do a permanant install.
There was another member here recently that was having the same problem. He corrected it by beefing up the grounds off the block itself.
You might try and increase the size of your ground straps on the driver and passenger side.
Its a quick test:
Take (2) 8 guage wires and temporarily run each one of them from the side of the block to the stud on the frame. If it corrects the problem, then just do a permanant install.
There was another member here recently that was having the same problem. He corrected it by beefing up the grounds off the block itself.
The concern i have is that i am worried that the low voltage may cause the pump to not supply enough fuel and possibly melt down..Sometimes driving normally the voltage bounces between high 12's and low 13s with out any really things drawing power..I would like to see a much more stable voltage just for peace of mind.. I am gonna try it regardless this weekend and see..
I want as much voltage at the pump as possible for better fuel delivery....thanks for the input..
I want as much voltage at the pump as possible for better fuel delivery....thanks for the input..
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
Ok, so this is what i did today..I installed 2 grounds straps..1 from the battery to one of the heads the other 1 from the alternator to the frame rail..I probed all the grounds on the pcm and found nothing wrong..I then installed 2 other grounds to the pcm..I used the existing bolts that keep the harness plugged into the pcn and ran a wire from both those boths to the ground under the battery tray..Nothing really changed..So now what???
I am wondering if it could be that my newly installed walbro 255 in drawing too much and that i need to install a hotwire kit..Could that be my problem?
I am wondering if it could be that my newly installed walbro 255 in drawing too much and that i need to install a hotwire kit..Could that be my problem?
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
Thought the problem was fixed.Crusing down the highway and the voltage wass pretty steady at 13.8..Then tdaywhile doing some test and tune passes at WOT the voltage drops..Do u guys think fuel pump may be drawing too much due to the factory wires?
Melting Slicks
Joined: Oct 2005
Posts: 2,877
Likes: 9
From: Ottawa Ontario
Mikey...I am not sure but all of the above seems fine to me. If you test the alternator and its above 14 volts and the battery is above 12 volts when car is off you are good with those 2 items. My car has bounced into the high 12's very momentaraly from what ...I don't know but like yours is around 13.2 - 13.8 under normal driving conditions and all seems fine. I have a Lingenfelter 255 pump with the boost a pump and 61 lb inectors and notice nothing out of the ordinary. I had a charging system issue last year and it turned out to be that i used the wrong solder when making a wire join for the alternators power wire. Take the boost a pump off and then take the car for a couple WOT and see if anything changes !
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
I installed a hotwire kit today and the volatge at my pump went from low 12s at the pump to 14.5..over 2volts just with adding the hot wire kit..I don't know if i figured out the voltage problem but i took care of the fuel pump voltage..I am gonna try the car later and see if the hot wire kit helped out with the voltage drw..
