charging problem

[Big Ox]

My 87 sub is not charging the battery. I did replace the alternater and the battery. PLEASE HELP

 

[spearchucker]

Is the belt on the alternator tight and not slipping?

 

[Dallin]

Do you have a volt meter? What is the voltage across the battery when the engine is running and with it off? Do you know what alternator you have? Does it have a 4 terminal connector or a 2 terminal connector?

 

[Big Ox]

The belt is new and tight.

 

[Big Ox]

The alternator is a 4 prong terminal. I think i am going to check the starter wires to see if they are bad.

 

[Indyblazer]

Check Battery Cables

1. I have had battery cables become corroded on the inside (where it was not visible) and not conduct the charging current. Feel the cables AFTER the truck has been driven for at least 10 minutes. If the cables are warm the are probably deteriorated and causing too much resistance.
2. Also look for corrosion (white powder) at the ends.
3. Have your battery load tested at an Autozone, Pepboys - you can't charge a bad battery.

 

[Big Ox]

I tracked it down to the brown wire from the four prong plug. But can't find the problem from there.

 

[justhorsinaround]

Dork boy!!! Drive it over here tomorrow night and we'll figure it out. Put a battery charger on it tonight though to make sure you'll make it.

I'll even let you use the volt meter.

 

[Dallin]

The L terminal (which I think is the brown wire) is the one that turns the alternator on. This wire should be hooked up to an ignition hot source. The wire needs a 35 to 350 ohm resistor in it. some vehicles use the warning light in the dash as the resistor.