Charging system problem

[Swamp Donkey]

So here is the deal. My alternator recently went out so i replaced it and it was running good for awhile until today. Today while driving around it started to act up and wanted to bog down and die like the battery was dead when coming to a stop but the battery light and nothing like that came on. I checked the voltage with the safc in my car and it was reading 12.0v or below so i hurried home and shut the car off. I then tested the battery with the car off and it was at about 12.7v so then i turned the car on and tested it and it was charging right around 14.2v. So then i went in and checked in on the safc and it was still reading no higher than like 12.5. I checked all the grounds on the battery and obviously the alternator is working because its charging at over 14v when tested with the multimeter directly at the battery. I don't know what else would be causing this, can someone please help me?

 

[1davho]

Sounds like a bad connection to the safc

 

[ileagle95]

Where did you tie the power in on the safc? Unless directly on the battery, it won't read 14.2. As stuff gets turned on, head lights, wipers, fuel pump, etc, it draws power.

An upgraded alternator will help Galant 90 amp, or saturn.

 

[GRAVEDIGGER]

Where did you tie the power in on the safc? Unless directly on the battery, it won't read 14.2. As stuff gets turned on, head lights, wipers, fuel pump, etc, it draws power.

Isn't that what the voltage regulator is for? To keep the alternator from over/under charging. You should still have system voltage throughout the car.

 

[Swamp Donkey]

I'm not sure where the safc is tied in to as it was in the car when I got it but the volt gauge in the car is also reading 12 or below at all times even when I check the battery and its reading at over 14. I have never had anything happen to me like this before. And even when driving the radio will cut in and out like it has no power. Could it be a short? Maybe a bad ecu?

 

[iceman510]

I suspect a bad or insufficient ground in the instrument panel area. Make sure all yours are clean and connected.

 

[Swamp Donkey]

I will check them but I can't imagine that would cause the car to bog down and lose power and die

 

[1davho]

Check the voltage at the fuses that are in the fuse box under the hood. It could be that the wires going from the battery tothe fuse box are corroded and/or have a loose connection.

 

[Swamp Donkey]

Ok I will do that. Also I'm not sure if its related to the problem at all but when I first start the car it idles really low and really lean if its just sitting, once I start driving it the air/fuels come down to normal and also as it warms up the idle goes up instead of coming down. When I first start it the car idles at about 800rpm and by the time it's completely warm the idle is up above 1500 rpm

Now the newest thing it is doing which i noticed while driving home from work is that whenever i would press the brake in the temp gauge would go all the way up and come right back down when i let off of it. It did this the whole way home but then when i got home and was sitting letting it idle and pressed the brakes it did not do it. I am very confused because i have never seen anything like this in all the years i have worked on cars. And also most of my accessories do not work like the sunroof, power mirrors, and blower motor and the windows didnt work but i rewired them so i could at least have windows.

 

[1davho]

Definitely sounds like bad grounding. Of you don't have a good chassis and/or block ground, power will start backfeeding through everything else and do all kinds of weird things

 

[Swamp Donkey]

Ok thank, I will go through and check/replace my grounds today when I get off work and see if that does anything

 

[Swamp Donkey]

Well i reran all the grounds in the engine bay and even added another one and that fixed the problem i was having. Now the only thing is its missing really bad and not just in boost. It ran fine right after i reran the grounds and i put new spark plugs in and then was out driving and it just started missing real bad. Any ideas what that could be? Do i maybe need to go to a colder plug?