Does your car do this?(voltage and shifting)

[timothylockhart]

Hello all I own a 2006 Grand prix 3.8 N/A

Few concerns. For one, I have the 5 Dic and measure my voltage alot as I will be putting in a car stereo soon, Alot of the time I notice that The voltage will sit at either 14.4-15v or it will sit hard at 12.9-13.0 This is seemingly random and I have never had an issue starting my car but I dont want to starve my car of voltage, I had it tested and the guy at autozone used the blackbar tester while it was on the car and said that it came back with 3 different codes so it was more then likely failing( He didnt seem like he was sure, he seemed new).


Second issue Is sometimes I will get in the car and put it to on or accessory, get a phone call or so and answer it, when I get off the phone I forget to turn on the car and attempt to shift it out of park, I have actually shifted it into Reverse before, Is this normal?

Also sometimes when i do start the car t will need a little bit of pressure needed to get it out of park to reverse.

car seemingly never hard shifts and transmission temp normally reaches 200 degrees after 30 minutes of expressway driving in 75-80 degree weather. highest it has ever hit was 213

 

[J57ltr]

The voltage fluctuation is normal. It's based on load and a few other factors.


Second issue I didn't understand what you are saying.


if your parking on a hill use the e-brake in neutral let off the brake, then shift into park.

Trans a temp is going to be at least as high as engine temp and higher. If you feel the need put in a trans cooler.

Jeff

 

[timothylockhart]

The second issue, Was sometimes I will accidently shift the car out of park when the car is not running, the key may be set to accessory or on but the car will not be running.

Also I understand fluctuating with loads, but the car will stay at 13volts and not go up for a 30 minute drive at times, With no loads on it, No ac, and daytime lights. I thought below 13.5v was bad?

 

[J57ltr]

That's normal the engine doesn't have to be running to get the car out of park. How else would you move a disabled car out of the way?

trust me we went round and round on this. The alternator only puts out what it needs to run things. If you notice on your negative wires you will see a loop around it. This measures current, both charge and discharge. There is an entire scheme the car uses to maximize gas mileage, bulb life, battery life, battery conditioning, everything has been taken into account on the car. It will drop as low as 12.5v and stay there for about 30 minutes and then rise to 13.8 for about 10 minutes then drop back and repeat that cycle. When lights are in it will maintain 13.8V to maintain the lumen rating of the lights. When you first start the car it will go as high as 15.1 then slowly drop.

Jeff