I have a 90' vette base with 48k miles on it. Over the last few months it has been very slow to turn over. Takes maybe 6-8 seconds to finally turn over and start up. A few weeks ago i noticed the voltage gauge on the display read about 8.5 volts when starting it and stayed that way for the 30 minute ride that i took. Headlights would dim when pushing the brake pedal, never stalled though. Hooked up a multimeter to the battery with car off , 12.5 volts. Turned the car on , tested with meter again , down to 12.0 volts. Friend of mine who has owned and repaired many vettes suggested replacing the alternator. We did that yesterday, same issue (most of the time). Occasionally it starts up fine and the volt gauge in the car reads 14-16 volts. He then suggested replacing the battery which was only 6 months old but maybe it had a bad cell. Got a top of the line battery and installed it.. still having the same voltage issues off and on. As a mater of fact, the multimeter is reading 11.80 volts when running. Now he is suggesting that I replace the entire dashboard cluster. He said they are known for going bad and causing these types of electrical issues. I'm just curious if anyone has had any experience with this and if it's true that replacing the dashboard cluster could fix my problem. Thank you for any assistance!

 

Replacing the Cluster not needed, they can go out spec. not a big deal you can remove it send it to Batee have them test it. Calibrate what's out and I sure if you specifically say you're problem that they will test for it

 

Do you think the dashboard could be causing the drop in voltage though?

 

Check the ground straps. You should have 13.6 or so when the engine is running.

 

First thing you need to do is get rid of your friend. You've received bad advise twice and replaced a part that may not have been needed. At this point the next thing you need to do is check to ensure that all your grounds are good.

 

You're more then welcome to text me I may help. Ray 734 775-0907

 

So it turns out the issue was the negative cable boot or whatever you want to call it. My motorcycle mechanic was able to figure that out after 2 hours. When he would tighten it , the car would shut down. Then loosen it and it would run but not go up to 14v. He cut the boot off and replaced it with a top post battery terminal. Car runs perfectly now. Back up to 14.5 v.

 

i ended up having to also change the positive cable connection and turning it into a top post battery terminal. The car is running fine and 14.5 volts when running. However, when driving at night and I push the brake pedal, the dashboard lights dim for less than a second and then return to normal when I release the pedal. The volt gauge also goes up like a quarter of an inch, if that, and then returns to its original spot at 14.5 v. Do I still have some type of electrical issue? Thanks!

 

Now that I changed the positive cable connection, the car is holding at 14.5 volts on the multi meter. It's no longer shutting down immediately. However the interior lights still dim when stepping on the break pedal or using the turn signal. It dims for a second and returns to normal as it "blinks". Also the voltage gauge needle moves slightly as there is a change in voltage as it blinks. A mechanic told me that it's perfectly normal for the dimming to occur momentarily and then return to normal. Is this true? i wanted to post a video but it wont let me. File is too large. While the vehicle is running and driving, the voltage gauge needle basically stays at this level... is that normal??