Alternator issues

[ferrall]

1994 5.8Fi

Just had my alternator rebuilt after it burned out. I just installed it and for a little while it showed a charge on the volt meter (~13V) but now it reads below 10V and my batteries got very low after a day on the lake. I am running 2 amps for my stereo. Could this be the issue or is there possibly more of an underlying one? What are some checks I could do? I'm not that great with electrical unfortunately.

 

[erie_guy]

Re: Alternator issues

My guess is that you are not charging the battery and your stereo is draining the battery in addition to your engine's electrical load. I would again check to assure that the alternator is charging the battery. I believe the charging voltage is 14.4 volts DC to the battery to achieve a full charge.
~13 volts will not adequately charge the battery. Make sure all electrical cables to the battery and the alternator are cleaned and re-tightened. I would recharge the battery overnight with a battery charger (plugs into a wall outlet) before taking the boat out again. You may not get back if you start out with a partially discharged battery.

erie_guy
Port Clinton, OH

 

[Glastron_V210]

Re: Alternator issues

You need to get a cheap digital voltmeter ($20 on sale).

To check if the alt is working:

1) Charge the batt so it will start.

When ti's done charging:

2) Check the dc voltage at the battery, engine off, key off. It will be somewhere in the 12V range. Write this down.

3) Start the engine and rev to 2500rpm and hold. Check the battery again. If it's higher, the alt is charging. If it's lower, the alt is not charging, or there is a connection issue between the alt and the battery.


It will take time for an alt to bring up a dead battery. You may require a larger battery if you want to run the radio all day long and not run the engine.

Chay

 

[bruceb58]

Re: Alternator issues

A fully charged battery at rest(not connected to a charger for an hour) will read 12.6V. With the engine running, battery voltage should be close to 14V. If it isn't, you alternator is bad or not wired correctly.

Like a previous poster said, buy a multimeter. Dash gauges are not accurate at all.