battery/alternator/????

[kwoods8851]

I have a crazy problem with my 84 Monte Carlo. My battery seems to run down when driving the car. If I drive it for about 20 mins then turn it off, it will not crank immediately. I can wait about five minutes and then it will crank. The battery and alternator both are fairly new. Another thing i noticed is the volt meter jumps around when i press the brakes or turn on the headlights. I'm preparing for a LS swap but I really wanna resolve this issue before the swap. Any help or suggestion as to what could be causing this.

 

[williamattop]

First and easiest thing to check would be all grounds and connections. Then make sure belt it tight(I think 1/4" deflection is correct), also make sure trunk/glove box lights are going off.
FWIW, these new(refurbished) alternators from your average chain stores suck. Last time I replaced mine, I had to return 2 of them within a 3 month period on a weekend driver. So I would get that checked also.

 

[87mcls305]

check the brown wire coming from the plug into the alternator it activates the charging of your battery...I had a similar issue recently

 

[Rowshak]

First and easiest thing to check would be all grounds and connections. Then make sure belt it tight(I think 1/4" deflection is correct), also make sure trunk/glove box lights are going off.
FWIW, these new(refurbished) alternators from your average chain stores suck. Last time I replaced mine, I had to return 2 of them within a 3 month period on a weekend driver. So I would get that checked also.

He's right, check your main ground and the second smaller wire that connect on the inside wall of the fender.
1)Just pull them out sand the surface and reinstall. Check if your battery is getting a charge from the alternator.

2)Start the car and connect a meter to the battery post ..watch if the charge is dropping. (12.00 , 11. 58, 11. 25 and it keep getting lower) if it does, take a wire from the positive post of your battery to the red wire on the alternator ( the one beside the brown one) without unpluging or stopping the vehicule make contact between them briefly and check right away with the meter if the battery got a charge ( It should have raise the charge from 11.25 to 15.00 or something like that).

If it did, there's a big chance your alternator is faulty or the power to the alternator is being cut off. Check the wires for any corrosion or splicing. And unplug your alternator and check if the connection are tight or bend (see picture)