Haven't had time to do any troubleshooting yet. I'm hoping you guys can save me some time by pointing me in the right direction.

Here are the symptoms -
When I try to start the truck after it has been sitting overnight, it behaves as though the battery has been drained, although the dash lights and stereo/amplifier still work. The starter starts to turn, then stops as if it can't get enough current. I use my booster pack & it fires right up.
Some type of parasitic drain right? ...but something else happened a couple times that is confusing me.

It did the same thing after work, but instead of jumping it, I drifted it forward, thinking I might drift start it.
I didn't have enough speed, but pop the clutch anyway and the truck stops. Then I try the key again and it fires right up. I've done this twice now.

Not sure if it's relevant, but I replaced the starter contacts a few years ago and the alternator in december. The battery is pretty old and everything else is stock w/220k miles on it.

Anyone have any insights about what is going on?

Thanks

Hook up a volt meter to the starter and see what happens when you crank it over:
http://www.4crawler.com/4x4/CheapTricks/Starter.shtml#EasyTest

If the voltage is dropping, then measure the battery voltage. If it drops, battery is the cause, if not, might be the cables (power and/or ground).

Dont forget to voltage drop the cables if you are suspecting the battery. i had a hell of a time with my terminal connectors, than i stopped buying the $1 connectors and spent the 5 bucks and never had a problem since.

How long has this problem been going on???? Sounds like possibly the gear on your starter motor is sticking (always engage with the fly wheel) thgen periodically it retracts such as when you tried to bump start. Check this right away because if the starter is spinning with the engine you will burn out the starter not electricaLLY but mechanically as the starter is not designed to spin fast.

Sounds like a marginal battery to me, check the voltages like others said. That it responds to jump says to me it's either a system drain or just a battery so close to dead it can't handle sitting overnight.

Dave

battery

Yup, was just the battery.
Thanks for giving me some direction.