alternator ?

[poolcues]

Got a 1993 c1500 350/4L60e. After the truck sits for about a week or so the battery goes dead, been doing this for awhile. The only thing I did since all this happened was to put in a new stereo. Pulled the stereo and it still happens.

The other day after charging the battery it wouldn't start, like it wasn't getting any fuel so after letting it sit for about 30min. I tried again and still no go.

The next day I used my other truck and a set of jumper cables and it fired right up. My question is, can the alternator cause it to not start?

Thanks for any help!!

 

[Fordum]

The alternator can only cause it to not start by letting the battery go dead.

Got a voltmeter? Crank it up with everything turned off. With it idling, measure the voltage across the battery. If you see 13.5-14.5 volts, odds are you either have a small short, or a battery going bad. Or a bad connection.

Turn off the truck, turn on everything electrical. Fan on high, headlights on bright.
Measure from the actual post to the post of the battery.
Assuming its a top post.
The battery should read from 11.5-12 volts.
If not, its either dead or defective.

If the voltage is in that range, put the voltmeter on the lowest dc setting, and measure from the center of the battery post to the wire just past the clamp on the same side of the battery.
In other words, from the positive post to the positive wire. Push the probe through the insulation.
You should see less than .5 volts.
Do the same on the negative side.

If you see . 5 volts or more, you have a bad connection between the two probes.
Usually a dirty clamp. but I have seen corrosion inside one of the molded on battery clamps where the wire goes in.

This test will only work with lots of load on the battery. So be sure everything is turned on while you are doing it.
Don't forget to turn it all off afterwards.

 

[ryoken]

Got a 1993 c1500 350/4L60e. After the truck sits for about a week or so the battery goes dead, been doing this for awhile. The only thing I did since all this happened was to put in a new stereo. Pulled the stereo and it still happens.

The other day after charging the battery it wouldn't start, like it wasn't getting any fuel so after letting it sit for about 30min. I tried again and still no go.

The next day I used my other truck and a set of jumper cables and it fired right up. My question is, can the alternator cause it to not start?

Thanks for any help!!

a short in one of the diodes in the alt can cause a draw... you can check for that with a test light or meter... iirc, disconnect pos bat terminal... hook light/meter to bat pos post, then touch the hot post of the alt, if it lights any, or draws any amps, it's got a draw...


but i would check for standard draws first.... hook between pos and pos connection, pull fuses to eliminate draw, etc...

 

[poolcues]

Thanks for all the help guys, gonna start chasing down the gremlin ASAP.

 

[kennyw]

Sounds like the problem I just fixed on my motorcycle... it was just a battery starting to go bad. It is very easy to test both the battery and alternator though. Just take them into any parts store for a free test if you don't have the tools to do it yourself.

 

[poolcues]

The battery is about 6 months old, still gonna run 'em both to the auto parts store for a checkup, that way they can replace the battery if it's bad while I'm there.